


Monsters of Monsters

by Tsaiko



Series: Monsters Under the Bed [1]
Category: Undertale (Video Game)
Genre: Alcohol, Alternate Universe - Underfell (Undertale), Anger, Anxiety, Awkward Sexual Situations, Bad Puns, Canon compliant level of puns, Canon-Typical Violence, Closets, Creepy Basements, Dogs, Drunkenness, Excessive Drinking, Existential Dread, Explicit Language, Falling In Love, Flirting, Food, For Science!, Frustration, Hangover, Happy Ending, Horror Tropes, Implied/Referenced Alcohol Abuse/Alcoholism, Implied/Referenced Character Death, Jokes In Poor Taste, Kissing, Literal Sleeping Together, M/M, Machines, Magic, Masturbation, Monsters, Nightmares, Not Really Character Death, Post-Canon, Puns & Word Play, Revenge, Robbery, Rumors, Science, Science Experiments, Scolding, Shorts, Sleeping Together, Slow Burn, Spoilers, Surprise Kissing, Threats, Threats of Violence, Throwing Things, Touching, Trauma, Undertale Monsters on the Surface, Unhealthy Coping Mechanisms, Unreliable Narrator, because these two do wind up together, but not actual horror, destruction of property, feelings of dread, it just takes awhile, kustard - Freeform, lying, monsters under the bed, rudeness
Language: English
Status: Completed
Published: 2019-07-08
Updated: 2020-02-02
Packaged: 2020-06-24 09:13:38
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 26
Words: 23,598
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19720669
Author URL: https://archiveofourown.org/users/Tsaiko/pseuds/Tsaiko
Summary: What if there was something under the bed?Sans shook his head. Where had that thought come from? There was nothing there.Or was there?





	1. Be Brave

**Author's Note:**

> I needed to work on something other than the Superheros story, and these are short and easy for me to do. Expect about 26 of them. Based on the list of things you do when you suspect there is a monster under your bed/in your house.

****

1\. Be Brave.

Sans woke up with a pain in his chest and a scream lodged in his throat.

The house was silent except for the ticking of a clock, the soft whirl of the trash tornado, and the sound of rain falling on the roof. Rain. There was no rain in the Underground. The world hadn't reset. They were still above ground.

Just another nightmare.

His bones were damp, soaked in the same cold sweat as his sheets. Sans rolled to one side, curled up against the world, and counted. Inhale for four, exhale for six. Inhale for four, exhale for six. Soon the frantic beating of his soul settled. There was a flash of lightning barely visible through the window and eight seconds later the distant roll of thunder accompanying the rain. He thought about laying down, but what was the point? It wasn't like he would be able to go to sleep.

There was a good – okay, 100% chance – that Papyrus was still up. Probably on the internet or watching TV with the sound off and the subtitles on. Sans could go sit with his brother until the lingering anxiety from the nightmare left. It happened often enough that Papyrus wouldn't even comment on it. Mostly.

He pushed off the blankets and sat up in bed. A bed. What a novel concept. As far as Sans was concerned, a mattress on the floor was just as good. Getting him a bed had been his brother's idea. Papyrus had insisted that now that they were on the surface, Sans should have a bed like a real adult. It just seemed like too much effort to argue. Besides, using a bed seemed like a small thing to do if it made Papyrus happy.

It seemed weird to have to climb out of bed after so many years of just being able to roll onto the floor from the mattress. Not a bad weird. Just weird.

His feet didn't quite touch the floor when he hung them over the side. There was a height joke to be made there, but Sans cut it short. Another flash of lightening. Another roll of thunder. Sans braced himself to put his foot on the floor.

And hesitated. What if there was something under the bed?

Sans shook his head. Where had that thought come from? The only things under his bed was a couple of wrappers, an empty soda can, and some socks he couldn't be bothered to retrieve. It was a place to collect dust, trash, and clothes. That was it. There was nothing there.

His foot hit the carpet with no issue, and Sans couldn't stop the sigh of relief. Then he laughed at himself. What else had he expected to happen? Sans shuffled unenthusiastically towards the door.

He shouldn't look behind him. Something might be watching.

What the fuck? Sans froze half-way across the room. The nightmare was making him jumpy or something. Why else would he think such things? Even though every bone in his body screamed not to, Sans turned around.

There was the window. There was the bed. There was the trash tornado, the dresser, and the pile of book stacked on the floor right next to the bed. What there wasn't was anything under the bed. Just shadows where the light didn't reach.

Lightening flickered showing through the curtain, throwing the edges of the room into sharp relief. There was... nothing under the bed. Absolutely nothing. 

Right. Sans definitely needed to go down and hang with Papyrus. Anything to keep his brain from thinking about things that definitely didn't exist. He turned around, and defiantly walked towards the door.

Behind him, red eyelights cut through the darkness beneath the bed. Those eyes watched Sans until the door shut behind him. Then the monster under the bed smiled.


	2. Watch a funny video.

**Summary for the Chapter:**

> No one ever told Sans that the thing ~~supposedly~~ under his bed could interact with the world.
> 
> Sans is not really pleased with this bit of information.

**2\. Watch a funny video.**

It was only eight o'clock at night and Sans was already in bed.

He wasn't sleeping though. Sans wasn't quite tired enough yet. It was just the cheap thrill of not having to get out of bed that saw him still in it. He'd been in bed all day long, leaving only to get food and find his phone charger when the battery had dropped below five percent. This was what his life was like when Papyrus went out of town for a few days. Living on the edge.

The remains of dinner – pizza delivery, humans sometimes had the best ideas – was sitting on the floor beside the bed. It made Sans's room smell vaguely greasy. Which was comforting in its own weird way. Kind of reminded him of Grillby's. Something Sans would have gotten had Grillby's delivered. 

Sans knew he'd have to put the rest of the pizza in the fridge at some point. He could eat maybe a quarter of the pizza in one sitting even if he loved it. Too much food just made him feel queasy. He never ordered pizza from the little local shop down the street when his brother was home. Papyrus said the sauce tasted too much like spicy ketchup. As far as Sans was concerned, that was a plus.

Currently, Sans was watching videos on his phone. It was another guilty pleasure. Not that he couldn't watch comedy with Papyrus around. He just had to be more... selective of his choices then. Without Papyrus around, Sans could watch all the mean comedy routines he wanted.

"Six weeks, people. Six weeks I've been waiting for them to give me access to this system. A system I need to do my job. And I find out that the only issue was that some guy in IT didn't want to sign a single piece of paper."

"After I told him what had happened, my co-worker replied 'Oh. You've met Speedbump.'"

"I was like 'Speedbump? Why do you call him Speedbump?'

"The guy looked me straight in the eye and said, 'Because the only thing he's good for is slowing everything down.'"

Sans huffed out a laugh at the joke. But something, _someone_ , found that statement even funnier because there was a sharp bark of laughter from under the bed. He froze. That hadn't actually happened... had it?

Before he could think about it and freak out, Sans was scrambling off the bed. He dropped down beside it. Underneath the bed was just shadows. Too many shadows. Was there something there in the darkness?

Nope. Not going to play at that. Sans got back up, teleported to the bathroom, grabbed the flashlight that Papyrus always kept in the top drawer, and teleported back. This time he turned the flashlight on and shined it up under the bed. The shadows disappeared.

Nothing. Well, nothing unexpected. Socks, a pair of shorts, two monster candy wrappers, and a lone soda can that had rolled towards the foot of the bed were all there.

Had the laugh been part of the video? Sans felt a bit ridiculous as he got to his feet, turning the flashlight off in the process. It took him a few minutes to find his phone among all the rucked up blankets, but Sans was eventually successful. He replayed the last minute of the video.

There was no laughter.

It didn’t make sense. None of it made sense. Sans was home alone. There was no one under the bed. And yet, he'd heard someone laugh and that sound came from under his bed.

"maybe i fell asleep." Sans hadn't, but it that seemed more likely than someone being under the bed. He put his phone down on the bedstand. Well, since he was up, he should probably put the pizza away. He'd kicked the box in his haste to look beneath the bed, and Sans walked over to it.

The lid was open. There were only two slices of pizza left in the box. 

Sans slept with the flashlight on and pointed under his bed for the rest of the night.

**Notes for the Chapter:**

> Yes, I did work at a place where one of my co-workers called a guy Speedbump. And yes, that was exactly the explanation he gave.


	3. Do not give in to fear created by your imagination.

**Summary for the Chapter:**

> It writes. It speaks! Oh crap, Sans has made a serious miscalculation.

**Notes for the Chapter:**

> Public Service Announcement: Do not Google "monster under the bed rules." You will not find the widely accepted rules that monsters under the bed are expected to follow. Instead you will find porn. So much porn. Obviously some people believe Rule 34 is actually a law.
> 
> Learn from my mistake.

**3\. Do not give in to fear created by your imagination.**

The problem... well there were a lot of problems with the situation. Sans had something living under his bed. Sometimes. Maybe. There was a possibility.

So far all Sans had was circumstantial evidence. Little things that were just... off. Stuff moved around the room. A wrapper for a candy bar swirling in the trash tornado that Sans had never eaten before. Red eyes in the dark that were there and gone when he blinked. A blanket that sometimes wound up under the bed. The heavy feeling in his soul that he wasn't alone even when no one should be in the room.

There was nothing he could point as evidence while telling his brother, or anyone really, what was going on. Papyrus would believe him. His brother was cool like that. Anyone else? Hell, half the time Sans didn't quite believe it. 

Why did it only appear at night? Why was Sans so convinced that light would make it disappear and keep it from reappearing? What was with the intrusive thoughts of horror and feelings of dread that always seemed to crop up? The problem was Sans kept reacting to the situation. He needed to be a bit more proactive.

Time to apply a little science.

Light was the first experiment. His weird instincts had been right. Leave a light on and the feeling that someone else was in the room never came. Leave the light off and there was a good 50/50 chance it would show up. Sans would know. He did the math to get that statistic.

Sans didn't need to be in the room for it to appear. That was the most surprising finding. He set up a couple of tells around places that seemed to generate the most activity: his bookshelf, the blanket, his desk. The chalk lines in front of the books smeared. The red mark in the corner of the blanket was no longer visible in the morning. The tape holding one of the drawers closed separated as it was opened. It couldn't be Papyrus. Papyrus didn't go into his room. That only left one culprit.

Food was another experiment. The carrots all too casually left beside the bed were untouched. So was the salad. And the kale chips. Papyrus had asked if Sans was feeling okay after that, which was why he'd switched to leaving out some Grillby's. That was a lesson in self-restrains Sans was not willing to repeat any time soon.

The burger and fries were gone the next morning. Heck, it looked like something had licked the burger wrapper. There wasn't even a speck of grease on it. Whatever was under his bed at least had good taste. Something animal like maybe? Sans picked up the trash only to see a scrap of paper with shaky writing in bright red ink.

_Next time leave mustard._

Holy shit. It could write. It understood words. Could it speak? 

It was nighttime, but not too late. Sans had been drifting off to sleep when it happened. That heavy, foreboding feeling that settle in his soul was back. He wasn't alone. Something was in the room with him. Sans rolled onto his back and stared up at the ceiling.

"hey. you there?" Silence. Sans laughed a little uneasily. "seriously buddy, i know you are there. just say something."

"Whatta'ya want me to say? Fuck you."

Sans would recognize that accent anywhere. It was the languid rolling cadence and dropped syllables of the streets of Hotland. Sans had spoken that accent when he was young. Before he'd worked hard to suppress it. The voice was also deep – like his – though with a rougher, almost sub-vocal growl to it.

Holy shit. The thing under his bed was from the Underground. He was a monster.

"no need to be like that." Sans could feel his soul pounding in his chest. A monster. Why had that not occurred to him before? "take it the burger was a hit."

"You don't gotta feed me."

"you sure? you even left a request. i can get you some mustard next time."

"Just leave me alone."

"that's not going to happen, buddy."

There was no reply. Just a sudden lack of presence. Sans took a deep breath in and let it out. Fuck. A monster. He should have known better than to treat someone like a thing.

Next time, Sans would do better.

**Notes for the Chapter:**

> Red you really are a little monster. You licked the burger wrapper. What would your brother say if he saw how low your manners have sunk?


	4. Do not wake the monster under your bed.

**Summary for the Chapter:**

> It's hard to have some alone time when you're not alone.

**Notes for the Chapter:**

> A chapter where no questions are answered, but the author thought it would be funny to write.

**4\. Do not wake the monster under your bed.**

Sans wasn't sleeping.

That seemed to be his life lately. His brain was doing the thing where it kept running around in circles, like a hamster wheel turned sideways. Sans was sorry he even got out of bed this morning ago. If he'd known he would be facing a bout of insomnia after waking up, Sans would have just kept sleeping.

He was so, so tired. And bored. But mostly tired. Sans couldn't focus on anything, which ruled out reading, or watching videos, or even thinking. Yet he was still bored.

Almost idly, Sans let his hand drift downward. His finger bones idly traced the ridge of his iliac crest where his shorts clung. He wasn't really into it. Not yet. But it was something to do. Something to force his mind to slow down.

As Sans touched his ilium, he felt his magic give the first faint stir of interest. Sans closed his eyes and sighed. He didn't even know if this would go anywhere. Sometimes it led to release and sometimes he got half-way through before his body decided sleep was more important that getting off. This might be the latter. His magic was certainly slow to respond.

So Sans touched himself, letting it build. Then he'd decide that it wasn't going anywhere, turn over, and settle down to sleep. Only to decide that maybe coming was more important. He'd turn back over, trail his hand back down, and continue touching himself. He had no idea how many times he went back and forth. Time didn't seem important.

Each time his magic burned a little hotter and the pressure in his pelvis grew a little heavier. Sans could feel his breathing speed up. Magic gathered in his joints. It felt good in a lazy, heated way. 

Nothing had formed yet. He wasn't that far along, and Sans kind of wanted to hold off. There was pleasure in holding back until it bordered on too much. Sans was enjoying it. Tracing the holes in his ischium left him gasping. Soon now.

*thump* *thump* *thump*

Sans froze, his hand still down his pants, and the heat of magic throbbing in his pelvis. He'd felt that. That had come from under the bed. Like someone pounding on the ceiling of some noisy neighbors to tell them to keep it down.

No. Absolutely not. It was his room and his bed. He was allowed to masturbate in his own damn bed. The knowledge that there was something - _someone_ \- under his bed listening to him was not helping with the whole getting off portion of the evening. His soul pulsed uneasily.

"i know you're there. do me a favor and just not listen for five minutes," Sans hissed. Almost immediately, the monster under the bed spoke.

"Five minutes? Seems like your sellin' yourself short."

That... was not a joke about height. 

"i'll have you know no one has ever complained about getting the short end of the dick with me," Sans replied.

"I don't know. That statement seems a bit premature." Sans snorted. Okay, that was a good one. "I ain't saying your size is the problem. Just your technique."

"sorry, i don't take criticism."

"Do you need some pointers?" There was some shuffling, like the monster was getting comfortable. "I'm awake now. Might as well give some advice. It's my one good deed for the year."

"yeah, you're a real boy scout." Sans had to preen a little at the sharp bark of laughter. His good feeling lasted until the other monster spoke again.

"Roleplaying is advanced shit. You can't even use your hand to get off."

"i don't need your help," Sans replied. Then he dropped his voice, because he did not want to have to explain to Papyrus what he'd been doing. "i know how the plumbing works, thanks."

"You sure? 'Cause it sounds like the pipe is clogged. If you can even find the pipe."

"oh fuck you."

"Promises, promises." The words were higher pitched and sing-song. Then the voice dropped back down. "What'sa matter? Gotta case of stage fright?"

The worst part was, the monster under his bed was right. It wasn't like Sans hadn't _performed_ for an audience before. He had. But there was big difference between doing a _routine_ in front of an audience and getting half way through a rehearsal before realizing that someone was watching.

"can you just be quiet?"

"Nope." The monster popped the p in an incredibly annoying way. "Not if you're going to jerk off above me. I was fine sleepin' my life away and you woke me up."

"i can make you go away."

"Yep. But then you'll have'ta deal with the fact that you sexiled me." The monster's words turned baiting. "What you waiting for? Or do you want me to hear? Gotta bit of an exhibitionist streak?" Then, once again in a sing-song voice. "I know what you're doing."

That proved to be the breaking point for Sans. He reached out and turned the light beside his bed on. The monster under the bed started laughing. There was a mean edge to the sound, harsh and knowing. Sans grabbed the flashlight he now kept by on his nightstand and shined pointed it under his bed without bothering to look.

Sans could hear the monster's laughter in his ears, even as it faded away.

Nearly an hour later, Sans finally succumbed to sleep. His magic still burned in his pelvis when he finally nodded off. Which explained why he dreamed about red eyes watching him as he touched himself.

**Notes for the Chapter:**

> I went back and forth over whether this chapter upped the rating or not for the series. Ultimately, it wasn't the masturbation that drove it into a mature category so much as the amount of cursing. These two have potty mouths and I thought that deserved more warning than a Teen rating would give.
> 
> Also, this is the longest chapter so far at just under 950 words. The goal is to keep each part under 1,000 so I managed it.


	5. Watch your ankles when you get out of bed

**Summary for the Chapter:**

> Sans does not react well to being unexpectedly touched. Most people don't. Then again, most people also don't have magic to react with.

**Notes for the Chapter:**

> My original outline had this chapter falling at the end of an arc (so chapter 6) with a short break afterwards. Then I realized people might murder me in my sleep if I did that. So don't worry! There is another chapter after this with no break in-between.

**5\. Watch your ankles when you get out of bed.**

In the two months since Sans had started interacting with the monster under his bed, he'd found out the other monster had exactly two moods: angry and asshole. That was it. Sans wasn't sure two moods was enough to constitute a personality. Then again, Sans really didn't have much room to talk.

The monster under his bed was there. Sans could feel the tension in the air, the oppressive feeling of dread that hung in his soul. It was kind of comforting. "i'm going to the kitchen to get some snacks. you want something?"

"No."

Ah. Tonight's mood was angry. Sullen anger, but definitely anger. "suit yourself. toriel made cookies. you not wanting anything means there is more for me."

"Hey wait."

That was all the warning Sans got. Fingers bones wrapped around the lower end of his tibia and fibia before he could dodge. It wasn't an attack. It was just the monster under his bed. It should have been fine. 

Fear raced up spine, choking back his words. There was no thought. His brain was filled with the white noise of terror. Sans made some sort of noise, a high pitched squeal. He couldn't seem to catch him breath enough to scream.

Sans had three strategies for dealing with problems: passivity, empty threats, and overkill. His brain by-passed the first two and went straight for the third. The electronic whine of four blasters charging filled the air. The monster under the bed released his ankle.

It was enough to jolt Sans back into thinking as opposed to reacting. What was he doing? It was too late now. The blasters were already fully charged, the sound shifting as they got ready to fire. Sans scrambled backwards to get out of the blast zone.

There was no way Sans could reabsorb that much magic. That didn't stop him from trying. He pulled back on the blasters, hard, trying to dissipate them. It didn't work. Sans didn't even have enough time to redirect them. They fired with a blinding flash and a staticky roar that was almost deafening.

The room plunged into darkness once more. The silence that followed the attack was eerily loud. Somehow Sans managed to find the light switch for the room. With the light on, he could see the damage. The bed was in four pieces and smoldering. Twisted bits of metal and smoldering cloth marked the path the blasts had taken through the mattress. There was a scorch mark covering half the wall behind it. 

Sans felt himself begin to shake. He wanted to laugh, but there was nothing funny about the situation, so he trapped the urge behind his teeth. The sound he made instead was small and hurt. He had gained no experience. His LV was still at zero. There was no dust under the wreckage that was his bed. Small mercies.

"SANS!" Footsteps pounded down the hall. Seconds later, the door to his room was thrown open hard enough that the doorknob embedded itself in the wall. Now the door was stuck open. 

Papyrus looked around wildly. There were several bone attacks floating in the air above his shoulder. "WHAT IS GOING ON?"

"bad dream." That seemed like the safest explanation. Certainly better than 'A monster has been living under my bed and I accidentally tried to kill him.'

"WOWIE." Papyrus surveyed the damage. "AT LEAST NOW YOU CAN'T COMPLAIN ABOUT HAVING A BED ANYMORE. IT IS _BED_ AND GONE. "

"good one, bro." Sans could tell he was shaking, his bones rattling faintly, but he didn't seem to be able to stop. "i guess i loved it to pieces."

Not his best pun, but it was worth the effort just to hear Papyrus scoff. "WELL. YOUR OLD MATTRESS IS STILL UP IN THE ATTIC, BUT IT'S TOO LATE TO GET IT DOWN. YOU CAN SLEEP IN MY BED TONIGHT. I WON'T BE USING IT BECAUSE I DO NOT NEED EIGHT HOURS SLEEP, BUT NOT EVERYONE IS AS GREAT AS ME. MY BED IS OPEN TO YOU. IF YOU WANT IT?"

His brother probably didn't mean for the last sentence to be a question. It hurt Sans's soul a little just how tentative Papyrus sounded. As if he could tell his brother "no" when he could give him something. "sounds great, paps."

That was all it took for Papyrus to start gently herding Sans out of his room. "TAKING CARE OF THE BED CAN WAIT TILL MORNING. LET'S GET YOU SETTLED."

The racecar bed was gone, replaced with a larger, wooden bed. An adult bed Papyrus had said. As if Sans wasn't aware that Papyrus was more of an adult than he was most days. Sans let him fuss over the blankets, the pillows, and whether to leave a nightlight on or not. After a good fifteen minutes Papyrus turned out the lights and closed the door. Sans was alone.

Being alone was was not as comforting as it once was. Sans stared up at the ceiling. He doubted he'd sleep the rest of the night, despite the fact the house had gone dark and quiet again. His thoughts kept coming back to one realization. Those were not fleshy fingers that had wrapped around his ankle. 

How had he never realized the monster under his bed was a skeleton?

**Notes for the Chapter:**

> Goodbye bed.


	6. If you feel breath on the back of your neck, something is definitely there.

**Summary for the Chapter:**

> Just when Sans though this weird chapter of his life was over, he realizes that no, it just got weirder.

**Notes for the Chapter:**

> Mirror, mirror on the wall.

**6\. If you feel breath on the back of your neck, something is definitely there.**

Two weeks. It had been two weeks since Sans had destroyed his bed. Two weeks of silence, of the absence of pressure in his chest, and of being truly alone when his brother left the house. Sans had been pretty sure he hadn't killed the monster under his bed. With every day he was getting more... worried was a strong word that required actual emotional effort. As was concerned. Resigned worked though. Sans was good at being resigned to things. And he was slowly becoming resigned to the fact that the monster under his bed was gone.

Sans was back to sleeping in his room. He and Papyrus had gotten his old mattress down from the attic just a few days after this incident. It smelled faintly, but it was still usable. That was an attitude leftover from the Underground. Don't throw anything away until it was useless. You never knew when you might need it again.

Right now, Sans was getting ready for bed by brushing his teeth. He hadn't bothered to turn the lights on. Papyrus had a nightlight in the bathroom in the shape of a couple of shooting stars. It provided enough light for Sans to see with, and gave everything a soft golden glow.

He was spitting into the sink when the nightlight flickered. Sans glanced at it, but the light stabilized and remained steady. Huh. Power surge. Wouldn't be the first time. At least the power didn't go out completely.

There was a small glass by the sink. Sans filled it with water, washed the last lingering taste of fake mint out of his mouth, and spit. Done. Now he could go to bed.

Except there was the faintest tickle of breath on his cervical vertebrae. Inhale cool. Exhale warm. It sent prickles of magic across his bones. Sans was suddenly hyper aware of the heavy feeling in his soul. He knew that feeling. 

Sans looked up and into the mirror.

There was a monster standing right behind him.

Not any monster. A skeleton monster. A skeleton monster that looked _like Sans._ He would recognize that face even if his own wasn't being reflected back at him in the mirror right beside it. Sans was looking at himself. Or at least a slightly darker, slightly larger, more emo version of himself. One with a cracked eyelight, jagged teeth, a single gold tooth, and red eyelights. A monster that looked like him wearing a fur trimmed leather jacket and a dog collar.

"Hey sweetheart. Miss me?"

Sans whipped around. There was no one behind him in the bathroom. Yet he'd seen him. He'd heard him. He looked back over his shoulder. There was the other Sans grinning his shark tooth grin, standing in front of him in the mirror.

Slowly, Sans turned back around. The other him laughed.

"Nice of you to give me your back."

"if you wanted me dead, you would have killed me already." That at least seemed like a safe bet.

"Sure. Right. Whatever helps you sleep at night."

"on reflection, i might have made a few mistakes," Sans admitted. The pun did not go over the other monster's head. The grin became less sharklike and more genuine. "seeing as we're mirror images of each other."

"Not quite." The other monster reached out, putting a hand against the mirror right over his shoulder. Sans should have seen an arm out of the corner of his eye. There was nothing there. "Still both assholes though."

Sans snorted. "i'm not an asshole."

"You are most definitely an asshole. An asshole who's sleeping on a mattress on the floor."

Guilt hit Sans like an aftertaste in the back of his throat. His eyes darted to the left, still expecting to see the monster standing behind him in the mirror. "sorry about that."

His doppleganger shrugged and took back his arm. "Shoulda expected it. If anyone grabbed me like that back home I woulda reacted the same. Don't worry. It had some unexpected side effects."

"now you're trapped in a mirror."

"Ain't trapped here. Ain't trapped under the bed anymore either. 's nice."

That made Sans narrow his eyes. "what does that mean?"

"You're smart. Figure it out for yourself." The nightlight flickered again, momentarily plunging the room into darkness. When it came back on a second later, the other monster was gone. Sans felt like he could suddenly take a deep breath. He hadn't even realized he'd been breathing shallowly until that moment.

Well. That was some cryptic bullshit. 

"asshole." The word sounded fond, even to Sans.

**Notes for the Chapter:**

> And so ends the first arc of this fic. I'll be taking a week off to work on other projects (Hopefully. Maybe. If work will stop sucking every urge to write out of me by requiring me to write things). Then this fic will be back for the next 6 chapter arc.
> 
> To all the readers who thought Red might be using his shortcuts to come and go: good guess! But nope, I'm really going whole hog on the monster under the bed scenario.


	7. The creak on the stairs means nothing.

**Summary for the Chapter:**

> Sans gets a name, a confirmation, and so many more unanswered questions

**Notes for the Chapter:**

> I found a website with an entire section devoted to skeleton puns. Can you tell?

**7\. The creak on the stairs means nothing.**

The first thing Sans realized when he woke up was that he'd fallen asleep on the couch again. This was becoming a habit. Despite the fact that Sans had slept on his old mattress for years, it felt wrong now. Maybe he'd just gotten used to actual back support.

The second thing he realized was that there was a reason he'd woken up. Something was moving at the top of the stairs, slowly descending another stair that creaked under the added weight. Three guesses who it was, and the first two didn't count. Sans glanced up and into the darkness.

Two red eyes looked back down at him. The TV was still on, the light from it blue and flickering as an infomercial played. The other monster didn't try to come all the way down. Instead he settled on the third step from the top. 

Pulling four blasters on people really did wonders for expanding your personal bubble.

"haven't talked with you much in the last couple of weeks" Sans said softly. It felt like the kind of atmosphere that called for quiet. That and there was a good chance Papyrus was still up. Sans didn't want to have to explain who he was talking to at 2am. "i was beginning to think you didn't like me any more."

"Yeah, well, not as much togetherness and interactin' and shit as before where I am now," the other monster said. His next words were deliberately neutral. It was hard for Sans to read his face in the dim light. "See your brother a lot more."

He would. Papyrus never really went into Sans's room much unless it was to get him up, and that would have been during the day. The other monster had challenged him to figure out where in the house he was... anchored to? Was that the right way to think about it? Anyway, Sans was pretty sure he was now haunting the super dark spot at the end of the hall. There should have been a window there. There wasn't. Now is was just the vaguely creepy spot near the bathroom where Sans could feel another presence if he lingered too long.

"don't let him see you." A pause as Sans considered it. "can he see you?"

"Tibia perfectly honest, I've been keeping a low profile around him." A shrug. "I don't know."

"i'd have a bone to pick with you if you kept popping up around him."

"Would you stop ribbing me as well?" Sans always did appreciate a good pun.

"don't worry, i won't stop jawing with you if my brother sees you," Sans replied. "just keep to the straight and marrow when it comes to papyrus."

"Heh." Sans narrowed his eyes. He didn't understand what had caused that laugh. It was short and devoid of humor. Or like there was humor in the situation, but the monster didn't find it funny at all.

"you have a problem with my brother?"

"His name is Papyrus." It was not a question, but a statement. 

Sans thought back to the incident in the mirror, looking at a reflection that was and was not his own. Did the other monster have a brother? Was his name also Papyrus? Did that mean their resemblance was more than just a creepy coincidence? He wanted to ask, but even thinking the question brought up a kind of soul clenching foreboding that stopped Sans every time.

"Not going to ask about it? Don't you want to know what my name is?" Sans narrowed his eyes. It almost sounded like the other monster knew he kept choking on the words. "You know my name. It's your name."

"sans." Somehow it was easier to say the answer than to ask the question in the first place.

Sans – the other Sans – didn't flinch, but his smile seemed to go brittle. "Fuck. That's goin' to get confusing quickly."

"so i'll give you a nickname." 

"Why don't you give yourself a nickname?"

"because i was here first, dumbass." That at least startled a laugh out of the other him, some of the strange tension seeping out of his posture. Fuck. The other Sans was right. It was confusing. "i could call you red."

"Red huh? Not very original." But Red didn't seem displeased by the name.

"what can i say? i learned my naming technique from asgore."

If he hadn't been watching for it, Sans might have missed the way Red flinched at that name. Interesting. It was a question for another time, assuming that Sans could get it out without a feeling of dread holding the words in.

Before he could bullshit any more, a yawn took him by surprise. Sans squinched his eyes shut. It was no use. He'd never been able to force himself awake when sleep demanded his attention.

"Idiot." Red's expression didn't exactly soften, but it grew less harsh. "Go to sleep. I'll keep watch."

"can i trust you?" 

"No." The answer was quick and decisive. It was tempered somewhat by the grin Red gave him, gold tooth gleaming in the low light. "But what else am I going to do if you dust? Read all your books until I can recite them in my sleep? Fuck that shit. It's sounds like work. I'll watch out for you."

Not the most comforting of statements. Strangely enough, Sans found himself drifting off almost immediately. Maybe he'd grown used to having someone in his room while he slept. It was dark, the blankets were warm, and someone was watching over him.

He had no nightmares.

**Notes for the Chapter:**

> Well the plan was for me to spend the two week break writing the next two chapters so I could get ahead for when I go on vacation in September. That didn't happen. So there will be an odd two week break in the middle of this arc. I suck at planning.


	8. What you see is a figment of your imagination.

**Summary for the Chapter:**

> As far as Papyrus is concerned, if you have a house guest, it's only polite to actually get to meet them.

**Notes for the Chapter:**

> The description of coffee tasting like regret is borrowed from the wonderful [ain't this the life](https://archiveofourown.org/series/896544) series by the awesome [nilchance](https://archiveofourown.org/users/nilchance/pseuds/nilchance)
> 
> I can find no better description for the taste of coffee. How something that smells so good can taste so not good, I'll never know.

**8\. What you see is a figment of your imagination.**

Papyrus didn't drink coffee. He said it tasted too much like regret. Sans hadn't been much of a fan of coffee until he started university. Academia was built on regrets and caffeine, so it was no surprise that he'd become addicted. Even after his advisor had taken himself out of existence by falling into the CORE and – ending Sans dreams of getting a PhD, making tenure, only teaching one class a week, and getting paid to think about physics for the rest of his life – forcing Sans to abruptly leave his program, he'd never kicked the habit.

Since Papyrus didn't drink coffee, he also didn't make it. Even when he got up before Sans. And Papyrus always got up before Sans. At this point, Sans no longer bothered to argue with him about it unless he just wanted the comfort of hearing Papyrus complain at him.

This morning there was coffee. Sweet, sweet coffee as black as the void until Sans dumped enough creamer in it to turn it milky. Sans stood beside the counter and ingested his caffeine.

"YOU COULD AT LEAST SIT AT THE TABLE AND PRETEND TO BE A CIVILIZED ADULT," Papyrus said. 

He could. But would he? Sans took another long drink, refilled his mug, and wandered over to the table. Slowly. Mostly to hear Papyrus huff in frustration. Less than a minute later a plate of toast and eggs was placed on the table. The eggs were only slightly charred, and you could even see some brown on the toast.

That was suspicious.

"what's the occasion?"

"DOES IT NEED TO BE AN OCCASION FOR ME TO MAKE BREAKFAST?"

"considering you hate coffee and you're not eating as well, yep."

And Papyrus... hesitated. That was worrying enough that Sans put his mug down on the table. Papyrus pulled out a chair and sat down. He made sure to meet Sans's eyes. His brother didn't have the ability to read people like Sans did, but it certainly looked like he was going to try this morning. "ARE YOU PULLING A PRANK ON ME?"

"no more than usual." 

"SANS." Behind Papyrus's usual exasperation there was a note of desperation. 

"what do you think i'm doing?"

"I KEEP SEEING YOU WHEN I KNOW YOU ARE SLEEPING. IT HAS TO BE YOU BECAUSE IT LOOKS LIKE YOU. ONLY NOT YOU? SINCE YOU DON'T HAVE RED EYES? BUT WHEN I GO TO LOOK MORE CLOSELY NOT YOU IS NOT THERE. I WOULD THINK IT WAS A SHORTCUT EXCEPT THERE'S NO SOUND."

"oh."

"YOU KNOW WHAT'S GOING ON." Papyrus looked hopeful. "TELL ME."

Now it was Sans's turn to hesitate. It sounded crazy. It was crazy. But was a monster living under a bed any crazier than what had happened to them in the Underground?

"there's a monster under my bed."

"I DON'T EVEN LET ROOMBA 2 UNDER YOUR BED."

Roomba 2 was the replacement for their first roomba, Roomba. Papyrus had been delighted by the little robot and insisted they refer to it by its name. Only then Papyrus decided Roomba needed an upgrade. Sans had come home from running his (still illegal) hotdog stand to find that Roomba had busted through the wall. He'd gently suggested that if he wasn't allowed to do experiments in the house perhaps Papyrus shouldn't either. His brother had looked at the Roomba shaped hole in the wall, then back at Sans before declaring "THAT'S FAIR."

As far as Sans knew, Roomba was still trundling forward in the wilderness in search of a wild charging station. Good luck, little buddy.

"i didn't let a monster under my bed. he just showed up and started living there. i haven't been able to figure out where he came from." _I haven't asked._ There was no reason to bring up that weird limitation. 

There was a long pause where Papyrus considered the new bit of information. Sans took a piece of toast and started nibbling one of the least dark corners.

"THAT'S UNSANITARY." Sans shrugged. Couldn't really argue with that. Papyrus drummed his fingers on the table, a nervous habit he had when thinking. "WHY DOES HE LOOK LIKE YOU?"

"his name is sans. like me. he might be me. or a me. a... different sans."

"WELL THAT PROMISES TO GET CONFUSING QUICKLY." There was another pause as Papyrus once again considered the situation. "IS THERE ANOTHER PAPYRUS?"

"don't know. i haven't met one." Sans considered this for a moment. "you haven't seen anything strange in your room, have you?"

"UNLIKE YOU, I DON'T SPEND EIGHT HOURS OF THE DAY IN MY ROOM DOING NOTHING." Papyrus frowned. "I HAVEN'T NOTICED ANYTHING STRANGE. BUT IF THERE IS ANOTHER SANS THERE SHOULD BE ANOTHER PAPYRUS. HOW WOULD YOU SURVIVE IF YOU DIDN'T HAVE ME?"

"i know there's another asgore." Better not to mention the flinch that had accompanied that name. "i know he can teleport. i know he likes mustard like i like ketchup. i know he has my sense of humor."

Papyrus made a noise of disgust. "THERE IS AN AWFUL LOT YOU DON'T KNOW ABOUT HIM."

"you know how i get about too many questions," Sans replied. Then he paused, considering how this whole conversation started. "most times."

"YES, YES. YOU ARE A BALL OF OBFUSCATIONS AND TERRIBLE JOKES. IF THE OTHER SANS IS THE SAME, IT MUST BE GENETIC. WHAT A SHAME."

"what can i say? i'm well bread."

A huff. "THAT JOKE NEEDS A TOAST-MORTEM."

Sans grinned. "it's last, but not yeast."

"IT IS A BIT KNEADY THOUGH." When Papyrus spoke again, his voice was much quieter. "Can I meet him?"

Uh-oh. "pap. i don't know." Papyrus opened his mouth as if to argue. "It took weeks for him to even speak to me. he's only around at night. he's kind of cagey."

"WILL YOU ASK THOUGH? IF HE WILL MEET ME?"

He never had been able to say no to his brother. "i'll ask."

**Notes for the Chapter:**

> I am so sorry Papyrus. I did not mean to drop you into an actual horror story where your house is haunted by a emo cryptid version of your brother that you only see out of the corner of your eye. My apologies.


	9. No one will be there when you turn around.

**Summary for the Chapter:**

> Unstoppable force meet unmovable object.

**Notes for the Chapter:**

> A short chapter due to illness. But it works.

  
**9\. No one will be there when you turn around.**  


There was absolutely no reason for Sans to be nervous. It was just... this was the first time he'd waited for Red to appear. Or really asked Red for a favor. Things would be different if it was something for him. Sans was used to disappointment. But this was for Papyrus, and Sans always hated disappointing Papyrus no matter how many times he managed to do so.

A sudden heaviness in the air was the only warning Sans had that Red was there. He'd deliberately left the lights off. Red didn't show up every night as far as Sans could tell, but he had wanted to increase the odds his doppelganger would show up tonight.

"Were you waitin' for me?" Red's voice was a mixture of sarcasm and self-satisfaction. Red eyes appeared in the darkness. "Couldn't get 'nough of my company?"

"well, i'm sure not here for your personality." Sans got up from his seat on the carpet. He did not want to have this conversation while being looked down on.

"Fuck you, I have a great personality." Red took another step from the shadows. There was a light on downstairs. Between it and the nightlight from the bathroom, Sans could see the glint of Red's gold tooth and the shape of his skull. His posture was relaxed. Sans could ease into the conversation, but sometimes these things were better if he just addressed them straight on.

"my brother wants to meet you."

"No."

Sans paused, waiting for an explanation. There wasn't one forth coming. Red's expression was shut down, giving Sans nothing. The other skeleton had tensed, but now he was deliberately relaxed. Too relaxed. Look at how much Red didn't care about his conversation. He was calling bullshit.

"why not?"

"Don't owe you shit."

"not even an explanation?"

"Nope."

Well. Here was a puzzle and a mystery. Sans might not be as good as his brother at puzzles, but that didn't mean he couldn't solve them if he put his mind to it. If he wanted to. Did he want to? Hell, maybe not for his own sake. But for Papyrus's sake? He at least wanted an explanation to temper his brother's disappointment.

"i'm not asking you to come to dinner. i'm just asking you to meet papyrus." Using the name was deliberate. Sans clocked the subtle flinch and tightening around Red's eyes. He could keep pushing, but Sans had a better idea. He smiled, making sure the just toe the line between sympathy and pity. "i understand though."

"Do you?" There was a lot of danger in those two words. The shadows seemed to grow, spilling down the hallway like ink and muffling the light. Sans stood his ground. 

"don't worry. soon you'll want to meet him. you'll practically be asking to make his acquaintance."

Just like that, the mood shifted. Red narrowed his eyes. "What are you planning?"

Sans just smiled. "i don't owe you shit."

*******

Three days later, Red found a note that had been left on the floor at the end of the hallway.

HELLO "RED",

MY BROTHER HAS TOLD ME THAT YOU ARE LIVING AT THE END OF THE HALL. THAT SEEMS LIKE A VERY UNCOMFORTABLE PLACE TO LIVE, BUT SANS ASSURES ME YOU ARE FINE WHERE YOU ARE. IF YOU NEED A BLANKET THERE ARE SOME IN THE CLOSET. WE HAVE EXTRA PILLOWS ON THE TOP SHELF AS WELL.

I HAVE ASKED MY BROTHER TO INTRODUCE US. IT IS ONLY FAIR THAT SINCE WE ARE GOING TO BE ROOMMATES FOR THE FORESEEABLE FUTURE THAT WE MEET. HE HAS TOLD ME THAT YOU HAVE DECLINED. I UNDERSTAND. IT IS VERY HARD TO BE INTRODUCED TO SOMEONE AS GREAT AS ME. I WILL CONTINUE TO BE AVAILABLE WHEN YOU ARE READY. 

SANS HAS TOLD ME THAT YOU DO NOT HAVE VEGETABLES WHERE YOU ARE FROM. THAT SEEMS LIKE A GREAT TRAGEDY. LUCKILY I, THE GREAT PAPYRUS, KNOW ALL ABOUT COOKING VEGETABLES. EVEN IF MY BROTHER WON'T EAT THEM UNLESS THEY ARE COVERED IN KETCHUP. I AM TO UNDERSTAND THAT YOU PREFER MUSTARD.

I HAVE LEFT YOU SOME VEGETABLES IN THE FORM OF MY FAMOUS SPAGHETTI FOR YOU TO TRY. I COULD NOT INCLUDE MUSTARD IN IT, BUT WILL TRY TO ADD SOME TO DISHES IN THE FUTURE.

PAPYRUS.

**Notes for the Chapter:**

> Man, I am so excited about the next chapter. The original outline had two completely different ideas for chapters 9 & 10, but the characters decided to go a different direction. For all that I complained, I can't say I mind too much.


	10. But there might have been.

**Summary for the Chapter:**

> Someone is spreading rumors about Red. Wonder who that could be?

**10\. But there might have been.**

"Stop telling your brother made up bullshit 'bout me."

The words were growled right behind him, coming from the dark as Sans made his way out of the bathroom and towards his room for the night. Red wasn't loud though. Papyrus was downstairs in the office on the internet, and Red wouldn't want to alert him to his presence. 

"i don't know what you mean," Sans replied. He schooled his face into the blandest smile he could manage before turning around. Red was right behind him, looming out of the darkness. He wasn't very effective at it. When you were only a couple inches above five foot tall, it was hard to loom.

"I know what a vegetable is, you prick."

"wow. someone must have started a bunch of rumors about you." Looking wide eyed and innocent was a stretch for Sans, but that didn't mean he didn't try. He put a hand over his soul. "the nerve of some people. i guess you should talk to papyrus and get that straightened out."

Red glared at Sans. Sans smiled back.

"Ain't gonna happen," Red said. He didn't look away though, and Sans had to wonder if this was some sort of dominance thing. First to look away lost? He certainly seemed intent on holding Sans's gaze. "Tell him to stop leaving food for me."

"tell him yourself."

"Asshole."

"takes one to know one," Sans said serenely. "come on. don't you want to keep the peas?"

"I..." Sans could see the exact moment Red caught the pun. Sans watched Red's eyes narrow. "That romaines to be seen. Depends on how big a jerk you're going to be."

"it's not like pap will be jalapeño business." There was that flinch again, subtle but there, at the mention of Papyrus's name. It was a piece of the puzzle Sans already had. He just wasn't sure he liked the picture that was being revealed. "don't squash his hopes."

"Olive this needs to stop." Red took a step closer. Sans refused to back away and refused to drop his gaze. Red eyes bored into his own. 

"or what?"

"Or I'll..." 

"IS THAT RED UP THERE?" Both Sans and Red jumped, giving the downstairs equally furtive looks. How had Red managed to get so close? Papyrus didn't appear. His voice was the only thing that intruded on them. "TELL HIM HELLO AND THAT I WILL MEET HIM WHEN HE IS READY."

"Ain't never gonna be ready." Red grumbled. He stepped back, shoving his hands into the pockets of his jacket, his shoulders hunched up until it was hard to see the collar around his neck. There was a fine sheen of nervous sweat on Red's skull. 

"ALSO THANK HIM FOR LEAVING THE EMPTY PLATE OUTSIDE MY DOOR. HE ACTUALLY RETURNS HIS DISHES UNLIKE SOME MONSTERS WHO JUST LEAVE IT TO MOULDER IN THEIR ROOM UNTIL I AM FORCED TO RETRIEVE IT."

"empty plate, huh?" Sans grin was delighted. His brother always did give him the best presents.

"I'm not gonna waste food," Red snapped. 

"uh-huh. was it spaghetti?"

"He made the noodles out of zucchini." That made Sans's grin go sharp. Red grumbled. "Tell him to cook them longer. Noodles ain't supposed to be crunchy."

"you could always tell him yourself."

"Why are you so focused on me meetin' your brother?"

It was on the tip of his tongue to deflect, to give some sort of bullshit answer. The words didn't come. What came instead was the truth. It was a surprise even to Sans. "because my brother wants something and i want him to have it if he can."

"Yeah." Red looked away, as if the wall in the hallway suddenly held the answers to the universe. "I get that."

"do you?"

Instead of answering, Red stepped back into the shadows at the end of the hall. His outline went indistinct until only his eyes were visible. Then those also faded away into the darkness.

Sans's smile felt more genuine. Red might play at being an asshole, but Sans could see through him. Mostly because he was him. Sort of. And anyone who praised and ate Papyrus's cooking couldn't be all that bad.

**Notes for the Chapter:**

> Red's brother was also a terrible cook when first started. So eating Papyrus's cooking was like getting smacked with bout of nostalgia. I bet he sniffled over those zucchini noodles though Red would deny it to his dying day.


	11. If you decide to cook something, always cook for two.

**Summary for the Chapter:**

> Food is always an acceptable peace offering, even if you're not going to stop making someone's life difficult.

**11\. If you decide to cook something, always cook for two.**

Papyrus was out of the house after nightfall – Undyne was dragging him out somewhere and Sans hoped they had fun – when he shortcutted upstairs. He could have walked. His brother would have scolded him for not walking. But honestly, Sans did not want to navigate the stairs while holding two plates with food on them.

"hey." It still felt weird talking to a dark hallway. Every time Sans did, he felt like this time he'd realize Red was all in his head and he had finally gone crazy. Tonight was not that time though. There was a sudden, reassuring pressure against his soul that sent a shiver down his spine. Two red eyes blinked out from the darkness. 

"What'cha want?" Red asked. His words were rough, like he'd just woken up.

"got food for you."

"More veggies from your brother?" Red emerged from the shadows like the world's most emo skeleton. "My bones are goin' to turn green from all the grass." Despite his words, Red still reached out for the plate Sans offered.

"it's not from papyrus. i... i cooked it."

That got his attention. Red looked up sharply from the plate. "You know how to cook?"

"tori taught me," Sans admitted. He sat down in the hallway, his back against the wall. "i got much better once we got to the surface. before that tori gave me instructions and i had to figure them out back at the house.

"She was was givin' you instructions through the door." Red looked like he regretted his words as soon as he said them. Another piece of the puzzle. Red had a Toriel as well and she too had locked herself in the Ruins.

"i heat to say it, while i have some skill-et following instructions, hands on was much more a-peeling."

"Heh." Sans was surprised when Red settled down near him in the hall. He wasn't touchy-feely at the best of times. Ever since the whole blaster incident, he usually left even more room between them. There was a brief burst of warmth to see him... not trusting, but not untrusting either. "I guess you were cooking at your own whisk."

"the first thing tori taught me how to make was pie. the first time i made it, it was so bad papyrus thought it was supposed to be a quiche."

That earned him another look, followed by Red eyeing the slice of pie on his plate. "Didja make this using the old lady's recipe?"

"no. i found it on the undernet." 

Sans didn’t understand why Red suddenly relaxed. He could ask. It was on the tip of his tongue to ask. Instead, Sans swallowed the words back. The food and a chance to just be companionable was a peace offering. Not that he was going to stop trying to get Red and Papyrus to meet, but he was sorry it had made Red's life more difficult.

"It's good," Red said, his mouth full of potatoes. Which was both disgusting and flattering. "Better than when I tried to cook."

"now you're just trying to curry favor," Sans replied. 

"I'm just grilled to see real food," Red replied.

That could have been a dig at his brother's cooking, but Sans refused to take it that way. He dug into his own plate with gusto. It wasn't a fancy meal. Roasting the chicken involved sticking it in the oven until it was cooked. The hardest thing about making the potatoes was not turning them into glue when mashing them. Including carrots was a nod towards his brother's desire to something healthy on the plate. It also helped that they didn't taste _green_. 

The pie was the most difficult thing to make. Sans had taken a shortcut (heh, he always did when he could) and used store bought crust and canned pumpkin. He didn't even need to add spices. The pumpkin came pre-spiced out of the can.

They ate in silence in the darkness of the hallway. Normally Sans wasn't a fan of silence. Too much room to think. This silence seem companionable. Intimate. Sans wanted to break the sudden weird tension in the air. He also wanted to stretch it out, let the tension between him and Red stretch on forever.

Red finished his plate with a loud belch, breaking the tension. Sans finished his plate and then let out an even louder belch. It wasn't like Papyrus was here to yell at him for it. Red laughed while San grinned. 

It was a good night.

Looking at the narrow space between then, Sans wondered if he could make it better. He carefully moved over until the space disappeared. Red stiffened. "this okay? i can move."

A long pause. "Yeah. It's fine." Red was a line of warmth against his side. As the seconds ticked by and nothing happened, Red relaxed beside him. Sans pushed more of his weight against Red. He smiled when Red pushed back.

"i'm not going to stop trying to get you to meet my brother," Sans said. Instead of arguing, Red just shrugged. "you might as well give in."

Red's smile was all shark teeth. "I'll think about it."

**Notes for the Chapter:**

> Red was asking about where Sans got the recipe, because he has talked with the Toriel from Underfell. She gave him a recipe for something called "Goodnight Pie." After all, it's hard to leave the Ruins to get yourself killed if you're too drugged up to stand. UF!Toriel was a bit... much.


	12. Do not worry about any of the above if you have a dog.

**Summary for the Chapter:**

> Maybe Sans and Papyrus should have stopped hammering on that button marked Trauma in Red's psyche.

**Notes for the Chapter:**

> Please mind the tag updates before reading.

**12\. Do not worry about any of the above if you have a dog.**

Papyrus kept leaving Sans alone in the house. He got it. He really did. His brother wanted Red to feel more comfortable in their house, and it was pretty obvious Red did not feel comfortable around Papyrus. So he spent more time with Undyne and Sans wound up spending more time with Red.

Normally, that would be fine. But over the last week or so something had gone off with Red. He was acting strange. Reclusive. Twitchy. Short-tempered.

Which meant it wasn't too much of a surprise when Red grabbed him from the darkness and got all up in his face. Sans figured it was only a matter of time before it came to a head. 

"Well, well, well. If isn't Sans lurking up in the hallway." Red's voice was friendly. His eyes burned in the darkness. "You think you're so safe."

"i'm in my house," Sans said. He tried for casual, but didn't know how successful he was. "what could happen?"

"I could happen. That ever occur to you?"

"i'm not afraid of you."

"Not now. You should be. Didja even bother checkin' me?" Red asked. There was a feral look in his eyes. He scoffed without ever letting Sans answer the question. "'Course you didn't. You think ain't nothing bad going to happen to you."

"you never checked me."

"Did too. First night I was here. You didn't even wake up." The last statement was almost sneered. Red's grip on the front of Sans's hoodie tightened. "You soft monsters are pathetic. It's all rainbows and kittens and shit for you. Don't have to worry 'bout people trying to remove your soul through your ribs here."

There was no way Red didn't see the flinch. Sans couldn't help it. The memories were lurking like darkness behind his eyes.

"Or maybe you do. How many times did the kid reset?"

"fuck you."

"Naw, not right now. I'm more in the mood for violence." Red's grin was vicious. "Don't know why you're even upset. Your bro is still alive."

The realization fell on Sans like a bucket of ice water. He remembered the feel of dust against his bones when he picked up his brother's scarf, the thin smile of the kid with dead eyes, the feeling of helplessness as he watched everyone die, the smell of bleach and lemon used to clean the Judgement hall. All the things Sans had tried to forget welling up like a poisoned spring.

Red gave Sans a shake. "Maybe I was wrong. Maybe things didn't always go right." When Red laughed, it sounded a little unhinged. "Go on. Check me. Won't even be mad."

Sans did. He wasn't sure it was a great idea, but he did it anyway. Sans magic washed over Red in a wave, before returning to him with the information he didn't want.

* SANS - HP 5/5 LV 9  
* He is grieving.

"fuck." Sans felt something sharp in his soul. And how long had he been pushing Red to meet Papyrus? He'd never thought of why Red kept declining. "i'm sorry."

"Don't you fuckin' dare." Red slammed him up against the wall, hard enough that Sans's teeth rattled. Not hard enough to do any damage to his HP though. "You don't get to apologize and think that's goin' to make it better. My brother is dead and yours is still alive. Stop rubbing it in my face all. the. time."

Magic surged in the air, so powerful Sans could taste it in the back of his throat. He braced himself for the attack. His own magic surged bringing with it a familiar mixture of anticipation and dread. This was going to be bad.

All fifty furry pounds of Annoying Dog suddenly came flying out of the kitchen at full speed. He watched as Annoying Dog barreled up the stairs, claws scrabbling and squeaky bark at full volume. Sans almost wished he had a camera. The look of pure shock on Red's face was priceless.

Sans thought it was a lot less priceless when Annoying Dog started circling Red while barking. Red turned towards the dog with murder in his eyes and bones forming around him. This was it. He was going to have to explain to Papyrus that his dog was dead because the mutt was trying to protect him.

Then he noticed that Red was fading out in front of his eyes. Red noticed it too. His grip on Sans's jacket loosened and he took a step back. Annoying Dog put himself between Red and Sans. Sans took a step back so he wouldn't trip over him.

"what the fu..."

Before he finished the last word, Red faded away. Annoying Dog stopped barking, prancing in place and giving Sans the look that meant he was convinced he was _a very good dog._ He wasn't sure whether to reward Annoying Dog's behavior or not.

He probably should. Annoying Dog had come to his rescue. "don't tell paps i told you, but there's some deli meat in the bottom drawer of the fridge beneath the lettuce."

Annoying Dog's tail was a blur of motion behind him before he raced towards the kitchen. Sans heard the refrigerator door open, the sound of a plastic drawer sliding out, and a triumphant bark. Then growling. Sans was definitely going to have to clean up the kitchen before Papyrus got home.

He looked at the kitchen, then back at where Red had stood just a few seconds before. His bones felt jittery from too much adrenaline. Red had tried to kill him. Or at least hurt him. _He had LV._

And despite everything, Sans still hoped Red was all right.

**Notes for the Chapter:**

> Two things:
> 
> 1) If you count the number of pixels in height he is and go off the assumption that Frisk is exactly the average height of a 12 year old kid (4' 10"), you come to the realization that Annoying Dog must be a medium size dog.
> 
> 2) The average weight of a medium sized dog is around fifty pounds.
> 
> The more you know.
> 
> If you would like to read the side story, [A Load of Crop](https://archiveofourown.org/works/21060524), this is the recommended place to stop and do so because of spoilers. Or do it whenever you want in the series. I can't stop you.


	13. Stay Awake

**Summary for the Chapter:**

> Sans is just kind of hoping things will go back to normal. Well, as normal as they ever get in his life.

**13\. Stay awake.**

Sans expected the nightmares to come back immediately. Being reminded of the resets? Remembering that he'd watched his brother die again and again? That was a recipe for Sans's own horrors to rise up in the darkness.

Of course, trauma never works like expected. The first five days after Red's outburst were some of the quietest sleep Sans has had in awhile. It was only on the sixth day, when Sans's mind gave him the thought _what if Red never comes back_ , that the trouble started. The idea that the last thing Red would remember about Sans was that he and Papyrus had brought up his brother's death made him feel a little sick.

And the nightmares returned.

It had been over a week now, and Sans hadn't had a single night of uninterrupted sleep. It was beginning to weigh on him. Papyrus was giving him the concerned look every morning. Even a brand new bed wasn't helping. Getting eight solid hours a night seemed like a distant memory.

Which was why Sans was awake to hear the sound from his closet just a little after midnight.

Had he actually heard a noise from the closet? Or was he imagining things? Sans was tired enough that it was hard to tell. Then he heard the noise again. Nope. That was real.

He still wasn't used to the height of the bed. It was slightly lower than his old bed, but definitely higher than a mattress on the floor. Sans's foot hit the floor sooner than he was expecting. It sent a painful, jarring sensation up his leg.

That didn't stop him from stumbling over to the closet. The door was closed. Sans put his hand on it. "red?"

Silence. It went on long enough for Sans to start to feel a little weird about talking to an empty room. He was reaching for the door handle, when there was a response.

"What d'ya want?" Red didn't sound angry. He sounded tired. Resigned. This was his life and there was nothing he could do about it. That was even worse.

"i want to apologize."

"Don't need your pity."

"it's not..." Sans managed to catch himself. Getting upset wasn't going to help. How did Red always manage to do this? No one else could get under his calm like Red. "i'm going to open the door."

"Whatever."

There wasn’t much light in the room: the pale glow of moonlight competing with the yellow glow of a streetlamp. Even less light reached the inside of the closet when Sans opened the door. Sans honestly didn't remember there being this much crap in the closet. Then again, he didn't often open the door except to throw more crap into it. Red's eye lights glowed in the darkness, watching him from the corner.

"so this is cozy."

A shrug. Sans could barely see it in the light. "I've slept in worse."

_But you don't have to._ Sans kept the words trapped behind his teeth. What he felt wasn't pity, but Sans was pretty sure Red would see it that way. "there enough room for one more?"

Another pause. This time, when Red spoke, there was a thread of emotion in his voice. "Why? You got a bed."

"yeah, but i'm not sleeping in it. i figured i'd try something else."

"Alcohol works."

That startles a laugh without humor in it out of Sans. He walks over to the bed and pulls off a blanket. "no it doesn't. just makes me depressed."

"Not if you drink enough of it." Maybe it takes another Sans to hear the dark humor in Red's voice. He hums an agreement. 

"i try not to let it get that far." The blanket it soft against his bones. "the one time i did, grillby woke me up with a bucket of snow dumped on my head."

Red's laugh was soft, but genuine. "Mine kicked my chair out from under me. Didn't do it there after that. If I was goin' to get really drunk, I did it on the couch." Sans threw the blanket over him as soon as he was in range. Red flailed a little bit until he got his head out. "What the fuck?"

"you're too boney to make a good pillow otherwise."

"Fuck you" The protest was half-hearted at best. 

"nope." It was a tight fit in the closet, but Sans managed. He leaned all his weight against Red's shoulder. "i live here now."

"Asshole."

"takes one to know one."

*******

Sometime during the night, the darkness and the warmth of the closet lulled him to sleep. When Sans woke up the next morning, Red was gone. Then blanket had been draped back over him. He felt a warmth in his soul that lasted until he saw the dick Red had drawn on his forehead in the bathroom mirror.

It took him almost fifteen minutes of scrubbing to get it off.

*******

Papyrus doesn't say anything when Sans asked him where the boxes were from when they'd moved. He helped Sans carry them upstairs to his room with only a minimum of scolding. When Sans started digging junk out of his closet, Papyrus silently helped him pack it into the boxes. Sans thought he'd figured out when he retrieved extra blankets and a pillow from the closet in the hall. But he didn't say anything.

They hauled the boxes up to the attic. Sans had so helpfully labeled them: stuff, more stuff, junk, crap, more crap, and stuff 2.0 to which Papyrus had added Electric Boogaloo. Once that was done, Sans added a flashlight and a stack of physics books to the closet next.

He stepped back to survey his work. Papyrus spoke.

"I'M GLAD RED'S BACK."

"me too."

**Notes for the Chapter:**

> Half way through the series and Red is in the closet. Oh yes, this relationship stuff is going well.


	14. Your friends cannot help you. You must face this alone.

**Summary for the Chapter:**

> Sans finally finds a piece of the puzzle courtesy of a small child.

**14\. Your friends cannot help you. You must face this alone.**

Sans wasn't much for kids – for many, many reasons – but he put up with them in order to see Toriel. The kids she taught at the school tended to be on the younger side which helped. He had more luck with the younger ones. They didn't always get his puns, but they loved his knock-knock jokes.

For the most part, Sans got around the issue by seeing Toriel after school or during her free period when she was still doing paperwork, grading, working on lesson planning, or doing whatever it was that teachers did. In this case, it seemed to be trying to balance a pencil on her nose. 

"knock knock"

Toriel jumped a bit, sending the pencil clattering to the floor. "Sans, you know you are not supposed to be in here." Despite her words, she smiled. "Who's there?"

He grinned. The policy was no unauthorized people on school grounds during the day and security all around the school enforce that policy. It wasn't very effective when monsters could teleport. "broken pencil."

"Broken pencil who?"

"never mind. it's pointless."

Toriel snorted as she picked up the pencil off the floor. "Did you come to see me just to share jokes with me?"

Both of them were always on the hunt for new material. Sans tended to search for jokes more often, but Toriel had an entire class of first graders who loved to share jokes with her. "have something a little more important to discuss." Despite being the one to bring up the topic, Sans hesitated. "have you heard any monsters complaining about things under their bed?"

From the doorway, there was a gasp. Sans looked over at the doorway to a human staring at him wide eyes. They were wearing a dark pink shirt with a glitter unicorn and floral patterned tights. The kid was at least a foot and a half shorter than he was. It was nice not to be the shortest person in the room.

"hey kid. i don't think we've met," Sans said, keeping his voice even and gentle. "i'm sans. sans the skeleton."

"Do monsters have monsters under their bed?"

It was a good thing that Sans had practice keeping his grin in place no matter what, because the little kid's question took all his words away. He looked at Toriel to see her reaction. Toriel just sighed.

"We talked about this Kaitlyn-child. Monsters don't live under beds. Fairies don't live in the woods. And humans don't have magic."

Now that was a familiar argument. Magic was everywhere in the Underground. Humans and some monsters, like Toriel, insisted that there was no magic above ground. Or at least, there hadn't been until monsters came above ground. The leading theory was that magic had been sealed along with the monsters, and only now was it beginning to leak out into the world above.

As far as Sans was concerned, that was bullshit. There had been magic above ground, just not as much as before monsters. It was there though. Sans could still see traces of it in movies and echoes of it in the stories humans told. 

Obviously those stories involved monsters under beds. Interesting. Maybe it was just the memories of old times, but Sans didn't think that monsters had _ever_ lived under beds.

Until now.

"let the kid talk," Sans said. "kaitlyn was it? what can you tell me about the monsters under the beds?"

"My parents say they aren't real," Kaitlyn said, ducking her head shyly.

"i believe you." Especially considering Red was now living in his closet. 

"The monsters live in the dark. They can grab your ankles so you have to be really careful when you... when you get out of bed. And... and they have glowing eyes. And they're really scary. You can tell when they are there because you can. They can't get you if it's light so I have a nightlight." All the words came out in a rush, piling one on top of the other. Then her voice got softer and quieter, as if Kaitlyn just remembered she didn't know Sans. "Sometimes they live in the closet. Closet monsters."

"have you ever seen a under-the-bed monster?" Sans asked. Kaitlyn shook her head.

"Kaitlyn, does Mrs. Jacobs know you inside?"

"I have to go to the bathroom," Kaitlyn replied.

"Then you should go and go back to recess." Toriel's voice was kind, but firm. Kaitlyn gave a shy wave to Sans before she disappeared. 

"You really shouldn't..."

"there's a monster living in my closet," Sans said, cutting off Toriel's words. "started off living under my bed like the kid said. he's upgraded."

"Sans..."

"no joke," Sans replied. "well, sometimes he's the joke. he also tells jokes. he's a sans. a more dangerous, darker version of me." Toriel went very, very still. That caught Sans's attention.

"I thought I was just hearing things," Toriel said. "At night. I would hear a voice that sounded like me telling jokes."

"what kind of jokes?" Sans asked. Amazingly, Toriel blushed.

"Jokes that I cannot repeat where little ears might hear them." Toriel shuffled the papers in front of her. "Why are they appearing now? What caused this?"

"i don't know. it could be excess magic manifesting itself using the humans belief system," Sans said. "or is could just be the universe fuc- um, messing with us." Toriel gave Sans a sharp look. "sorry, forgot there were kids around." And he'd been spending too much time around Red.

"But they are still monsters." It wasn't a question so much as a statement.

"yep."

"I know I am no longer your ruler, but someone should help them. If they need help. If they want it." Her eyes were kind, but knowing.

Toriel always did have too much faith in him. "i'll see what i can do."

**Notes for the Chapter:**

> This was one of those chapters where I knew I was going to write it, I just wasn't sure how it would go. Sans had to find out that humans believed in monsters under the bed somehow, and I figured a kid from Toriel's class was a good way to go.
> 
> The knock knock joke was just an added bonus. As was the idea of UF!Toriel telling raunchy jokes to Toriel when she had trouble sleeping.


	15. Never turn on the lights.

**Summary for the Chapter:**

> Sometimes, despite an experiment giving you the exact result you expected, you still find yourself surprised at the results.

**15\. Never turn on the lights.**

The first thing Sans did was research. It wasn't as easy as he was hoping. The internet was millions of times bigger than the Undernet, and filled with about a million times more weird stuff. That was saying something considering the Undernet had multiple moldsmol porn sites.

After wading through the horror movie pages, the band album pages, and oddly enough the porn sites, Sans was able to do actual research on monsters under the bed. It wasn't very enlightening. Humans thought monsters under the bed were nothing but kids imagination.

Yeah, he had an emo bastard currently living in his closet that said otherwise.

Sans was able to piece together one commonality. Monsters under the bed could only come out in the dark and disappeared during the day. Light kept them at bay. There wasn't much more than that beyond advice on how parents could calm their kids with fake "monster repellent" or white noise machines. It seemed that kids believing monsters lived in their rooms was so universal, no one bothered to describe them.

It was quite possibly the shoddiest research methodology Sans had ever had to deal with. And he'd had an advisor who tended to forget no one could read his font and write half his notes in wingdings. 

"You're up late." The voice carried from his closet to his desk. Sans had his desk lamp on, but the rest of his room was pitch black.

"trying to figure a few things out," Sans replied. His eye sockets ached. That's what he got for putting in actual effort.

"Need help?"

"mostly i need to sleep," Sans replied.

"Can't help you there. I'd invite you back to my place, but I have too many skeletons in the closet as is," Red replied. Sans didn't doubt it. No matter how much he and Papyrus moved out, Sans's closet was still small.

Which gave Sans an idea. He needed to sleep. Red needed to sleep. There was a perfectly good bed. No one else seemed to be able to articulate the rules of how monsters under the bed interacted with the world. Maybe it was time to experiment. 

Or maybe Sans just wanted to share a bed with Red. That was something to think about. Later. When he wasn’t so tired.

"hey red, what do you call a skeleton in the closet?" Sans walked over to the closet as he spoke. He could hear Red moving around as he got closer. The closet door was open and Sans could see red eyes watching him from near the closet floor.

"Don't know. What?"

"human hide and seek winner." The joke was a bit more morbid than Sans's usual fair. Which meant that Red loved it. Sans used his laughter to locate Red in the darkness. His fingers closed around Red's ulna and radius in the dark. The bones were thick and a bit rough. 

"What'cha doin'?" Red didn't sound upset. More curious than anything. It didn't fool him. He could feel the sudden weight in the air, a tension that hadn't been there before.

"an experiment." Sans gently pulled Red up. There a brief resistance. Then Red decided to go along. He got up. There was another hesitation at the closet door. Magic ran across Sans's bones before it settle again. Red stiffened.

"How did you get me out of the closet?" There was a bit more strain to Red's voice.

"an experiment," Sans repeated. He pulled Red towards the bed. "one that involves you sleeping in an actual bed."

"Well, I love my bed, but I'd rather be in yours." Sans looked back to see Red leering. He rolled his eyes.

"just to sleep, asshole. even if somnophilia is your thing, keep it in your pants" This time Red's smile was a little more genuine.

"Or what? You'll kick me out of bed? Just means we can fuck on the floor." Despite his words, Red didn't try anything as they got into Sans bed. Which was a lot more difficult when Sans was trying to keep a hold of his wrist. Red didn’t bother to take off his jacket. He just kicked off his shoes and slid under the sheets. "Now what?"

"sleep." Sans closed his eyes as if to demonstrate. Red huffed a laugh, then shook his arm until Sans loosened his grip. He slid his hand down until fingers intertwined with Sans's. Holding hands. It was just practical. Never mind that it was also the most romantic gesture Sans had ever experienced. 

That thought still lingered in his mind when Sans drifted off.

*******

Sans woke to his own face.

No, not his own face. He didn't have a gold tooth or a cracked socket. Red's face. They had fallen asleep in his bed. Now it was morning and his hand was still in Red's. 

Light filtered through the curtains. It was morning and Red was still there. Chalk one up to the scientific method. Sans watched Red sleep, noting that the circles under his eyes looked less dark. Sans had the urge to lean forward and kiss him. The impulse sat heavy on him, but he resisted it. Red looked different when he was asleep. Not younger. Less tense though. Sans found he didn't want this to pass, wanted to hit pause and hold on to this.

Time marched on though. More light came in through the windows. Red grumbled, turning his head into the pillow. "Five more minutes, Boss..."

Regretfully, Sans let go of Red's hand. Red slowly faded, his form growing more indistinct until the sheets crumpled back to the bed. There was only a faint, lingering warmth to indicate he'd even been them.

An experiment.

And Sans wasn't sure what the result told him other than he was getting in deep.

**Notes for the Chapter:**

> You know, you two were originally supposed to kiss like ten chapters ago.


	16. Logic and reason will not help you in the dark.

**Summary for the Chapter:**

> As more pieces of the puzzle fall into place, Sans begins to develop a theory

**Notes for the Chapter:**

> I'm trying to write this relationship fic,  
> But my plot is dummy thicc  
> And the sound of my plot points keep alerting the characters   
> that they're experiencing feelings.

**16\. Logic and reason will not help you in the dark.**

Sans hadn't been down in the basement in a long time. Months really. He paused on the stairs, hand over the light switch, and facing the darkness, as he thought about it. The last time he'd been down here was before Red had showed up. Obviously, Red had proved to be a much more interesting subject than trying to get the machine fixed.

The basement flooded with light when Sans hit the switch. Despite this, it still looked dim. It always looked dim no matter how bright a bulb Sans put in the fixture. The light never seemed to quite reach the corners.

There wasn't much down here. The machine was down here, obviously, lurking in the farthest corner of the basement. There was also a table, a couple shelves, a chair, a toolbox, and a cot folded up against the wall for when Sans wanted to take a nap. He never wanted to take a nap near the machine. Just working on the machine triggered nightmares for days which in turn triggered his insomnia. They were wolves in sleep's clothing.

Sans wasn't really sure how the cot had gotten down here. He would think that Papyrus brought it down here, but Papyrus never come down here. They had the spoken rule about no experiments in the house and an unspoken rule that Sans could do whatever experiments he wanted to as long as they stayed confined to the basement.

Sans picked up the flashlight on the table as he went by. The flashlight helped counterbalance the weird dimness in the room. When it worked. Sans turned it on then smacked it a few times to get it working. The light it produced was weak. He pointed it at the machine.

Yep. That was the machine. Looked just like it always did. A few months ago, Sans would have described the feeling as terrifying. That wasn't the case. The response he had when Red did something creepy was terrifying. It got his magic moving, filled his bones with adrenaline, and forced him to react. The machine was something else entirely. It was quiet menace and existential dread. The kind of thing that made him want to curl into a corner and just give up.

The machine had always been more Gaster's project than his, even though the theory of it was based on his thesis. Gaster's expertise was integrating magic and science. Sans was content to know just enough about magic to understand physics.

Sans had started working on the machine to try to bring Gaster back after the whole CORE incident. He was not throwing away six years of hard work just because his advisor was an idiot who science himself out of existence. Then he'd worked on it as a form of self-punishment. This was where science got him. Nightmares and reboots and a feeling of helplessness when it all went wrong. Did he really want to do that?

The answer was yes. Kind of. Sans still hoped to get the machine working one day just to prove that his theories were correct. Maybe he'd manage to bring Gaster back. Or at least a Gaster from a world.

Sans froze half way across the room. The flashlight in his hand fell to the floor and flickered off. He ignored it. A Gaster. Like a slightly twisted version of himself that just happened to appear after he last messed with the machine.

There was a theory there, a breakthrough that Sans could see the edges of but couldn't yet articulate. But more important than the why was the how. How had the machine started working? When had it started working? And why was it not working now?

With just a few steps, Sans was across the room and examining the machine. It was plugged in, but not on. It never came completely on no matter how many times Sans flipped the switch. Now it sat like a dead thing. No lights. No sound. Nothing.

What had he been working on? Sans walked back to pick up the flashlight, hitting it several times to make it turn back on. The beam picked up the back panel, which was missing two screws. He had been working on the wiring. There was a screwdriver sitting on the floor from he hadn't bothered to put in the last two screws.

Seconds and a few curse words later, and Sans had the panel off. The inside was covered in black soot. It didn't take him long to find the culprit. A fuse had blown.

Would a blown fuse be enough to cause two worlds to collide? Was that what really happened? Sans didn't think it was. But what if the magical fields were still in flux when it happened? He was so close to understanding but the details were frustratingly vague.

Not for the first time, Sans wished Gaster was still around. He knew enough physics that Sans could bounce ideas off of him, but not so much that he was set in his thinking. Sans could talk to Alphys, but Alphys could only listen. She couldn't contribute.

But... he could bring one edgy bastard who was him down here to look at it and get his opinions. Sans had caught Red reading his copy of "Introduction to Superstrings and M-Theory." So he had to at least know the basics of physics.

He'd have to hold Red's hand the entire time. Sans felt magic rise to his cheeks as he turned the flashlight off. This was ridiculous. He was ridiculous. There was no reason to blush. All he was doing was hold hands. He'd done a lot more and a lot worse in college.

Still, it would be a good excuse to get some more physical contact in with Red.

Yeah, he was definitely going to bring Red down here.

**Notes for the Chapter:**

> The characters and incidents portrayed in this story are fictitious. No identification with actual persons (living or deceased) is intended or should be inferred, and the plot is definitely not inspired by that one committee member that I had bribe people to tell me when they were in the office so I could get them to sign off on my thesis. Not that I am bitter.


	17. In case of a robbery, having a monster in your house is a good thing.

**Summary for the Chapter:**

> Most monsters were not stupid enough to try to rob the Judge. And now there's one set of humans who have learned not to rob monsters.

**Notes for the Chapter:**

> I knew I was going to be writing this chapter from the moment I saw the advice on the list I'm using for chapter titles. There was no way I was passing this up.

**17\. In case of a robbery, having a monster in your house is a good thing.**

The first clue that something was wrong was the missing TV. Sans stopped in the middle of the living room and stared dumbly at the blank space where it had been. Papyrus didn't notice. He was too focused on getting to the kitchen and putting the groceries away.

"SANS DID YOU LEAVE THE BACK DOOR OPEN?"

"no. television is missing."

"MISSING? WHAT DO YOU MEAN MISSING?" Sans could hear the sound of Papyrus closing the door. "TELEVISIONS ARE NOT USUALLY MOBILE. THAT'S MUCH MORE A TELEPHONE THING."

"i think we've been robbed." Sans immediately began to look around to see what else was gone. The cushions on the couch were disturbed, which struck him as funny. What were the burglars looking for? Loose change?

"WHERE IS THE DOG?" Papyrus had sounded curious about the door and resigned about the missing TV. There was a note of genuine panic about Annoying Dog. Sans teleported to the kitchen just in time to hear a faint whimper from hall closet. 

Papyrus got there before him. He threw the door open and Annoying Dog immediately ran out. "THERE YOU ARE. YOU SHOULDN'T WORRY US LIKE THAT. WE MIGHT THINK SOMETHING HAPPENED TO YOU."

"it would be a ruff time for us."

"SANS!" Something must have caught Papyrus's eye, because he leaned into the closet mid-scold. "WHERE DID THIS COME FROM?" Papyrus asked. He held up large piece of rawhide, bleached white and shaped like a bone. Papyrus never let Annoying Dog have those types of toys. First, because he'd read on the internet that rawhide could splinter. Second because he didn't want to encourage Annoying Dog to chew on anything bone shaped.

There was no question where the dog poo in the closet came from. Annoying Dog must have been in there for a while. He wagged his tail hopefully at Papyrus. Sans could have told him it was wasted effort. That treat was not going to be returned.

"some guard dog you are," Sans said, even as he gave Annoying Dog's ears an affectionate scratch. 

"WE SHOULD CHECK THE REST OF THE HOUSE TO SEE WHAT'S MISSING," Papyrus declared. Then he hesitated. "SHOULD WE CALL SOMEONE? THE POLICE ARE THE TRADITIONAL CHOICE."

"we can," Sans said. If he thought about it, Sans could follow Papyrus's logic. It wasn't like crime was unheard of Underground. People got greedy. Or desperate. Or bored. When they did, they tended to steal. However, there were few monster stupid or brave enough to steal from the Judge. Which implied that this little caper had been done by humans. "let's take a look around first."

The basement door was still locked and the dead bolt still closed. Sans felt a moment of ridiculous, belated anxiety when he saw it. What is the thieves had gotten to the machine? They obviously hadn't, but the "what if" made anxious sweat spring up on his bones. Papyrus found that someone had unconnected all the cables from his computer. The only thing missing was the power supply, which was found half-way down the hall.

"it looks like something stopped them."

"I THINK I KNOW WHAT." Papyrus was looking up towards the second floor. Sans looked as well. Part of the bannister was missing as though it had been vaporized. Part of Sans's door was still in the frame, but a large hole was carved out of the center. It almost looked like a blaster had gone off, but Sans was the only monster he knew of that...

Red.

It was pure instinct to teleport to the top of the stairs. There were more scorch marks on the wall, holes from a bone attack, and a place where the floor had buckled slightly from where someone had brought up a bone wall. The damage seemed to be centered around Sans's room.

Sans went inside. Surprisingly, everything looked normal. A brief look around showed nothing missing or out of place, except that the closet door was open. 

"THE DESTRUCTION WOULD BE A LITTLE HARD TO EXPLAIN TO THE HUMAN POLICE," Papyrus said as he surveyed the damage in the hall while standing in the doorway. "THE GUARD MIGHT BE A BETTER CHOICE EVEN IF THERE ARE HUMANS INVOLVED."

"red drove them off," Sans said.

In his mind, Sans could see it. Had Red confronted the burglars in the stairwell? Had he hid in Sans's room, listening to the humans getting slowly closer as his anxiety increased until he'd finally snapped? Had he been woken up from a nap by the sound of a doorknob turning and unfamiliar voices at the door? Sans felt a little sick at the thought.

"WE CAN ASK HIM ABOUT IT TONIGHT." Even as Papyrus was speaking, Sans was shaking his head.

"he doesn't show up for a couple of weeks when he used a bunch of magic. or when he's attacked." He hadn't been around last night either, but that wasn't unusual. Red didn't show up every night. Sans had been disappointed he couldn't share his revelation about the machine immediately, but he'd been looking forward to talking shop with Red tonight.

So much for that idea.

"Oh." That seemed to take some of the wind out of Papyrus's sails. He was as worried as Sans was, but trying to cover for it. "I AM SURE HE IS FINE." 

"i hope so."

**Notes for the Chapter:**

> To be fair, none of the scenarios Sans pictured actually happened. Red heard the burglars the minute they came through the front door. He just waited till they were up in the hallway before firing a friendly warning shot because he wanted to make sure they were actually not supposed to be there. And because Red, like Sans, doesn't believe overkill is a bad thing, his friendly warning shot was in the form of his strongest attack.


	18. Do not say ’If you are there, show yourself'. Sometimes they do appear.

**Summary for the Chapter:**

> Sans is not having a good day, but at least he's got some good news.

**Notes for the Chapter:**

> You're welcome.

**18\. Do not say ’If you are there, show yourself'. Sometimes they do appear.**

The worst part of the robbery was dealing with the aftermath.

Sans had called the guard and the dogs had responded. Not that there was much they could do. The dogs had picked up a scent, but it disappeared as soon as it hit the streets. The robbers probably got into a car. They were mostly there just to take an incident report. 

It wasn't like they were going to get their television back. Sans knew the odds, and they were not in their favor. But Sans knew that if he wanted to file for insurance – because he'd actually read all the paperwork they handed him before signing – he needed to have a report of what had happened. 

Turns out Sans should have called the police. At first, the insurance company hadn't accepted the guard's report as legit. A quick call from the embassy had cleared that up and the guard's report was considered equivalent to a police report, even if it had a paw print on it. Then they'd asked for a receipts. Like Sans had a receipt for a television that had been rescued from the dump. He'd submitted as much bullshit paperwork as he could. The insurance company had told him they'd respond in four to six weeks. Now it was a waiting game.

Sans was pretty okay mentally. Break-ins were a thing. They happened. Nothing to be done. Papyrus wasn't quite as blasé about the whole thing. He couldn't leave the house now without checking that all the doors and windows were locked. Sometimes multiple times. It made Sans want to hunt down the people who did this and put the fear of monsters in them. As if Red hadn't already done that.

At least he could turn his anger and annoyance towards the insurance company. It was better than worrying about his brother. Or Red. Especially at 3am when he should be sleeping.

Sans turned over in his bed. His brand new bed. The one Papyrus had bought because he'd blasted the other one when Red had grabbed his ankle. If he hadn't needed a new bed, then they would have been able to afford a new television instead of having to deal with insurance. 

Fuck, sometimes it felt like the universe was against him and nothing he did mattered.

The night was quiet except for the wind. It moaned around the house, not constant, but coming in irregular gusts. They didn't have wind in the Underground. Not like this. No monster Sans had spoken with slept well when it was windy. Especially when the wind made it seem like the whole world was wailing.

He breathed in and breathed out before turning over. A chill raced down his spine, making him shiver. There was a weight to the air, like oxygen itself had grown heavy. It pressed against his soul. It made Sans's bones shake. He did his best to muffle the noise. He had to stay quiet. Otherwise... it might hear.

There was something under the bed.

It couldn't be Red. It had only been a week. It had to be Red though. Sans wanted, desperately, for it to be Red.

"Red?"

No answer. Just the heavy weight of the realization that he was not alone. Sans took shallow, careful breaths. He was afraid to disturb the darkness too much. It didn't stop him from speaking again. His name sounded strange on his tongue when he was referring to another.

"Sans?"

"How do you know that name?" That was not Red's voice. It had a higher tenor, like Papyrus's, but with the same gravelly note that Red's had. "Where is Sans?"

 _Right here._ The words were trapped behind the panic that was rising up in his throat. Sans scrambled back on the bed as it the other side of the mattress would save him from whatever was beneath him. 

"Tell me." The voice demanded. Sans watched in a kind of slow motion horror as a hand reached up from under the bed. It was all bone, with sharpened claws at the fingertips that sank into the mattress. "Tell me where he is."

Sans snapped from his trance with a whimper. He lunged for the flashlight he kept on his bedside table, dodging the claws that swiped at him at the last second. Light. He needed light. That was one of the rules, right? 

"Where is Sans?" The words were snarled. Red eyes glowing in the darkness appeared beside him. He couldn't get the flashlight on. Where was the button? Terror made him clumsy. "What have you done with him? WHERE IS HE?"

Finally, finally the flashlight decided to finally start working. The beam caught the monster right in the face. The breath catches in his throat. He can't speak. He can barely breath. Sans immediately recognized him even with a scar and jagged teeth.

Papyrus. Or a Papyrus. Red's brother. Holy shit, he was alive. And Sans had just managed to shine light on him, because fuck his life. At least the other Papyrus didn't yell or scream. He just faded away with the same familiar annoyed expression Papyrus wore whenever Sans said a particularly bad pun. 

What he did leave behind was a series of very impressive gouges in Sans's mattress. Even as Sans watched, the fabric gave way and a spring uncoiled. Awesome. First Red broke his bed and now not-Papyrus took out his mattress. The property damage brothers at their finest.

Sans started laughing. And if it was just a bit hysterical, that was no one's business but his own.

**Notes for the Chapter:**

> I have sat on this plot twist for FOURTEEN CHAPTERS. How I managed not to just blurt out "He's alive, I swear." I'll never know. 
> 
> Two week hiatus for Thanksgiving after this chapter and then we'll start the final arc.


	19. It helps to be on friendly terms with the monster under your bed.

**Summary for the Chapter:**

> Sans tells Red what is going on, and Red is grateful.

**Notes for the Chapter:**

> I was not expecting to sit down this afternoon and have the ENTIRE CHAPTER written in one sitting, but I am not going to complain.

**19\. It helps to be on friendly terms with the monster under your bed.**

It was nearly three weeks later – long enough for Sans to worry, but not long enough for him to panic – before Sans felt Red's presence. And by presence, Sans meant Red's foot kicking the mattress from below.

"Fucker. You there?"

He was now. Sans scrambled off the bed, ignoring the sudden spike of fear and anticipation when he put his feet on the floor. "i'm here. i am also not going to be responsible for my actions if you grab my ankles."

"Now why ya gotta go and put it like that? Makes your ankles tempting." He didn't grab Sans's ankles. But Red did trail phalanges against the sensitive end of his tibia. Sans jumped back with a sound that was definitely not a squeak. Red laughed.

"asshole." Was it weird that Red seemed to be in a good mood? Or was it weird for Sans to feel a spark of warmth at the realization Red was in a good mood? "come out. we need to talk."

"Is this about the idiots who broke into your house?" Sans watched as Red's hand emerged from the darkness, pale in the darkness. He could barely make out the shape of Red's bones. There wasn't much light in his room. He'd gotten in the habit of keeping it dark ever since he'd decided to encourage Red to join him. "Because I ain't apologizing."

"i'm not asking you to," Sans replied. He reached down to grab Red's hand, and helped pull the other skeleton out from under the bed. "i should charge for the door though."

"Yeah, yeah. Put it on my tab," Red said. His grip tightened on Sans's as he maneuvered his legs up under him. "It was worth it to see those fuckers' faces. I didn't realize humans' eyes could bug out like that. Wish I had a camera."

"you don't have to sound so gleeful." Sans made sure to interlace their fingers before turning on the nightlight Papyrus bought him. Red's fingers tighten briefly. 

"Why not? It was hilarious. Not often I get to bring up the big guns." Red's smile turned predatory. "At least the big guns not in my pants."

Somehow, Sans managed not to let his gaze drop downward. If he had, Red would never let him live it down. "keep it in your pants, buddy. i got some news for you."

"What? Need me to protect you and your brother from someone else?" The words were mocking, but there was a genuine question underneath. Red would protect them. Sans had to fight back the smile that threatened, even if he wanted to grin. Red did not need to be encouraged to cause any more destruction.

"the goal is to leave the house standing," Sans replied. His grin took out any sting from his words. Then Sans hesitated. There was no good way to say this. Better to rip the bandaid off and hope the wound was healed underneath. "i think i ran into your brother while you were gone."

Red's fingers tightened around Sans's almost to the point of pain. Sans endured it. Red's eyelights disappeared and his face went rigid. "What?"

"Red eyes. Jagged teeth. Clawed hands." Sans tried to picture what the other Papyrus had looked like in his mind, but terror had made the memory blur and vague. "He had a scar across his eye and a red scarf around his neck."

"He's alive?" The words were tentative, like Red had been given an unexpected gift but didn't trust it. Too afraid the universe would change its mind and snatch it back. "He's alive. Fuck, I should have known." Red's laughter was just a bit too hysterical to be called happy. His grin was pure delight, and his accent grew thicker in his joy. "Shoulda known. Ain't nothin' goin' keep Boss down."

Sans laughed with him, enjoying Red's happiness. He wasn't expecting for Red to suddenly lean in, pressing their mouths together. It was barely a kiss – Sans's didn't even react. When Red stepped back, fingers still entwined with Sans's, he was smiling like he'd won something.

No. Sans could not let that stand. He pulled Red forward sharply. Red came willingly. Their teeth clashed together at first, before Sans tilted his head and manifested his tongue. The sound Red made was both surprised and appreciative.

Soon Red's tongue was sliding against his own, bright red against electric blue. There was the static buzz of magic where their tongues met. It had been a long time since he'd done this. Sans gave a shaky little noise, which Red swallowed. In return, Red groaned. The sound came from deep in Red's ribcage. 

Somehow, Sans managed to step back. He didn't quite know what to make of his reluctance to end the kiss. It was something to think about. Later. Much later. Possibly with his hand down his pants.

"Heh." Red's grin was softer now. Sans could feel a blush creeping up his throat. Which was ridiculous. It made Red's smile grow sharper. The bastard. Sans's mind flailed, looking for a distraction.

"boss? that his name?"

"You know what his name is. Papyrus." Red was still grinning. "I call him Boss because he's the boss. Ain't that hard to figure out." Red paused, looking thoughtful. "You goin' give him another name like you did me?"

"probably, yeah." Sans cleared his throat. His voice was rough, and his magic pulsed in his joints. "i'd ask you for suggestions, but i'd probably get stabbed if i took them."

That startled a laugh out of Red. "Yeah, probably." His fingers squeezed Sans's briefly. "He's alive."

Sans squeezed Red's fingers back. "he's alive."

**Notes for the Chapter:**

> I don't Sans, you and Red seem to be a more than "friendly" terms with each other. :D


	20. Nothing is waiting for you downstairs.

**Summary for the Chapter:**

> Is the machine involved? Sans has a few theories. And now, he has someone to bounce them off of.

**Notes for the Chapter:**

> This chapter fought me at every dang word.

**20\. Nothing is waiting for you downstairs.**

"i've got something to show you," Sans said. He doesn't want to break the moment between them – the moment where Red seemed happy – but it has to happen. Time moved forward unless there was a reset.

"Do you now?" The leer Red gave Sans made him roll his eyes. "I'm sure it's same as what I got but I'm willin' to be proved wrong."

"it's not in my pants."

Red's smile turned even sharper. "Hey, that can be even more fun."

Sans got a sudden flash of just what Red could be referring to. In lurid detail. It shouldn't be this easy for Red to fluster him, and yet Sans could feel the painful prickle of a blush on his cheeks. He coughed to cover his discomfiture. "not that either. perv."

"Can't blame me for havin' ideas." The claw on the end of Red's finger traced lightly against Sans's bones where they were still holding hands. "We can always share a bed again."

"or you can stop trying to jump my bones and follow me."

"Heh." Sans noticed that Red was easily pulled along after him. No idea where he was going, but Red was willing to trust him. The feeling it gave Sans was sharp and sweet. He let it wash through him, but doesn't examine it further.

They crept down the stairs. The light was on in Papyrus's room. Red hesitated when he saw it, and the look he gave the room was a mixture of longing and trepidation. Sans squeezed his fingers. "he'll be happy to meet you when you're ready."

"Whatever." But that didn't stop Red from sneaking another look when he thought Sans wasn't looking.

The house was dark, but Sans knew the way. Down the stairs, cut through the corner of the living room, into the weird little not quite a hallway, and then past the door. If Red thought the fact that there were locks on the door to keep something out, he didn't say anything. The stairs to the basement creaked and groaned under their weight. Red's fingers tightened around Sans's as they descended into darkness.

He turned the light on.

"What the fuck is wrong with you? You brought that thing _into your house_?" Well, that answered the question of whether Red knew about the machine. Red took a step towards it, then seemed to remember he was still holding hands with Sans. He gave him a quick tug. "Creepy piece of shit."

"where is the one in your universe?" A guess, but a good one given the evidence. "still back in the lab?" The look Red gave him was disbelieving. 

"You think I'm goin' leave that thing around where someone with more curiosity than sense can turn it on to see what it does? Fuck no. It's sitting in a cave in Waterfall. I hope it rusts." Despite his words, Red was already walking over the machine. "Panels look different."

"did you get yours working?" Sans asked. 

"Sorta. I could turn it on. Then it was a 50/50 chance of whether it would stay on or blow a fuse." He'd found the panel Sans had left loose, by-passing the screw driver and using his claws to pry it out. Handy. "Tried to keep it off as much as I could. Didn't trust it." Red immediately noticed the soot on the inside. "What happened?"

"funny story that." Sans settled down on the floor beside where Red was kneeling. "i left it plugged in over night..."

"Why didja do somethin' stupid like that?" Red asked. His eyes blazed with anger. "You coulda at least put in on a surge protector. It's a wonder it didn't create a black hole and suck the whole neighborhood in it."

"i didn't realize that would be a problem. we had the CORE in the underground." The reality of what Red was saying made Sans reconsider his next words. "did you have the CORE?"

"Yeah, we had it. But we lived in fuckin' Snowdin. All those transmission lines got tore up just about every other damn day. Slowed down when the Boss took over control of the guard in town, but..." Red cocked his head, assessing. "Did you guys live in Snowdin?"

"yep. had a house and everything. papyrus wasn't in the guard. he was trying though," Sans replied. "never had issue with the electricity."

"One time the lines got destroyed during a Mettaton special. Thought Boss was goin' turn the entire bun clan into vacuum food. They didn't do that again. Hell, electricity was most reliable when Mettaton was on after that." Red examined the wiring while spoke. "Wirin' is shit. I'm surprised you haven't electrocuted yourself yet."

"it's a shocking procedure, but i'm alive." Red snorted. "you're welcome to rewire it. you'd be doing me a favor. i always was better at theory than hands-on stuff." Sans handed Red some wire cutters as he spoke, disentangling their fingers and sliding his hand to Red's wrist. "if we get it fixed, we might be able to do something about your allergy to lightbulbs."

"You think this..." He made a gesture that could have meant just the machine or the panel with covered in soot. "... has something to do with why me and the Boss are here instead of back home?"

Sans grinned. "it's why i brought you down here. let's talk theories."

**Notes for the Chapter:**

> Edge was not mad because he missed the Mettaton special. He'd been looking forward to a night in, that got ruined, and he was pissed about it. It just happened to also be a night that the Mettaton special was on. Red, on the other hand, told everyone that would listen that it was because of the Mettaton special because that's what older siblings do: annoy and embarrass their younger siblings. They'd take away his annoying older brother license if he stopped. Can't have that.
> 
> The fact that no one messes with the electricity in Underfell when a new Mettaton show is on is just an added bonus.


	21. Don't bother remembering where you put things. They'll have moved by the time you look again.

**Summary for the Chapter:**

> Red meet Papyrus. Papyrus meet Red.

**21\. Don't bother remembering where you put things. They'll have moved by the time you look again.**

They didn't go down the mess with the machine every night. Red, like Sans, could only be around the machine for so long before it started to give him nightmares. Red still wanted to go down there every night to see if he could get it working. Sans put them on a strict "two nights a week" rotation. Since Red could only go where Sans led him, Sans got his way.

The rest of the time they spent getting to know each other. Now that Red was sure his brother was alive, it was like a dam had broken. He talked. A lot. Sans was just as talkative. Somehow it worked.

Their favorite thing to discuss was the difference between their universes. Sans would mention some facet of the Underground, and Red would either talk about how it was different or agree it was the same. Then Red would mention something about his Underground. They would go back and forth trading tidbits of information between them while holding hands in the dark and pressed against each other.

Neither of them ever brought up the resets. They weren't stupid though. There was enough context clues for them to realize both of them had experienced them. Even years later, the resets were too raw for them to discuss.

In order to spend more time with Red, Sans had started going to his room almost as soon as it was dark. Then he stayed up as late as he could. Which meant he was tired during the day. Sans had fallen asleep at his hot dog cart more than once in the last couple of months.

Of course Papyrus would notice. He had been making vague – for Papyrus – comments about how tired Sans was for the last two weeks. Sans had been ignoring them or giving vague answers. Of course, Sans should have known 

He just wasn't expecting Papyrus to find an excuse to corner him in his room. Neither was Red.

One second, they were encased in comfortable darkness. The next second, the door to Sans's room was thrown open. Light spilled in from the hallway, making Red flinch. 

"SANS, I TOLD YOU I NEEDED ALL YOUR LAUNDRY. I AM NOT GOING TO GO DIGGING THROUGH YOUR... oh." Papyrus

Thank the Universe he and Red were still sitting on the floor talking and not curled up in bed against each other like they usually were. Papyrus would have never let Sans live it down. Red had gone still beside him. Sans stroked his thumb over their joined hands soothingly. "hey paps. give me a second?"

"YES, OF COURSE." Papyrus immediately turned around.

"Wait." That came from Red. Papyrus stood still in the doorway. There was a long pause where Red just looked at him before he slowly got to his feet.

"YES?"

"Heh. Figured it was time I met you," Red said. He pulled on Sans's hand until Sans also got to his feet. Sans obediently followed him across the room. Papyrus turned around to face him. "Gotta happen sometime."

Papyrus took a deep breath. "IT IS VERY NICE TO MEET YOU. UM... RED?"

"Yeah, that'll work." Red's smile went slightly lopsided. "Not my real name though."

"NO, THAT WOULD BE SANS. LIKE MY BROTHER," Papyrus replied. "I DIDN'T REALIZE SANS WAS GOING TO BED SO EARLY TO BE WITH YOU." The look he gave Sans was sly and he waggled his brow bones. "IT CERTAINLY EXPLAINS WHY HE'S SPENDING SO MUCH TIME IN BED AND IS SO TIRED DURING THE DAY."

Sans immediately covered his eyes. "paps, no."

Red let out a bark of laughter. "I ain't been tryin' too hard to keep him up at night. Didn't want to keep you awake with all the noise."

"dude." Sans pushed at Red's shoulder. Red just pushed him right back.

"I WILL BE SURE TO WEAR MY NOISE CANCELING HEADPHONES IN THE FUTURE," Papyrus replied. Sans looked like he wanted to sink through the floor. When Papyrus next spoke, he sounded uncharacteristically hesitant. "I UNDERSTAND YOUR BROTHER IS AROUND. I WOULD LIKE TO MEET HIM AS WELL. IF HE IS WILLING."

"I'll ask when I see him," Red replied. He sounded confident that he would see his brother. It made Sans's soul hurt, but in a good way.

"we still need to get him fully in this world," Sans said. 

"We're working on it," Red added.

"I HAVE FAITH IN YOU, SANS. WHEN IT COMES TO TERRIBLE SCIENCE THAT COULD DESTROY THE WORLD IF IT WENT WRONG, YOU ARE THE EXPERT." Papyrus laid a hand on Sans's shoulder. "UNTIL THEN, I STILL NEED YOUR LAUNDRY."

Luckily, most of his dirty laundry was in the clothes basket. Most of it. Red helped by going under the bed to retrieve a couple of socks and a pair of shorts that had wound up down there. Sans did his best not to watch Red squirm with his brother standing _right there._ A few minutes later and it was done.

"IT WAS NICE MEETING YOU RED." Papyrus said as he left the room.

"You to," Red replied. He waited until Papyrus left the room before saying anything else. "At least he didn't give me the shovel talk. Can't say the Boss will be as nice to you." 

"something to look forward to," Sans replied. He wasn't going to be scared off that easily. 

Red was looking off to one side, but there was a faint dusting of red across his cheeks. "Meetin' the family is an important step. Ya know. In a relationship."

Sans grinned as he tightened his fingers around Red's. "it sure is."

**Notes for the Chapter:**

> You know things are getting serious when your significant other starts talking about introducing you to family. :D


	22. Light attracts them.

**Summary for the Chapter:**

> Red has met Papyrus. It's only fair that Sans meets Edge.

**22\. Light attracts them.**

Sans was half-way to the basement door, Red beside him, when he remembered that the light bulb had blown out when he went to grab something from the basement. Red might be fine in total darkness, but Sans needed light to see. And as much as he trusted Red, he also trusted Red to be Red. If Sans couldn't see, he was just setting himself up for a night of terrible pranks.

"detour time," Sans said. He turned sharply left and headed towards the kitchen.

"Why?" 

"i need to get something." There was a weird, tiny cupboard that was wedged between the refrigerator and the wall. It was too small and too out of the way to put anything they used regularly in it. Papyrus has seen a new segment touting the benefits of having an emergency preparedness kit. Since that cupboard was useless for anything else, that's where he'd put it. Sans pulled one of the emergency lanterns and clicked it on. The light wasn't too bright, but Red still flinched when he turned it on.

"What's that for?" Red asked grumpily. Sans sighed.

"no matter how long bulbs are supposed to last, they usually blow after a few months near the machine," Sans replied. 

"Might not be the machine. It might just be shitty wirin'." 

"do you really believe that?" Sans asked. Red shrugged. Which was all the answer Sans really needed.

The basement seemed much more forbidding without the overhead light on. The emergency lantern wasn't that powerful to begin with. It seemed to get even dimmer with every step down the stairs. Sans pushed through the foreboding that overwhelmed him. Stupid machine.

"Why should you never ask a skeleton to change a light bulb?" Red suddenly asked. Sans wondered if he could feel Sans's tension, or if he was covering his own unease.

"why?"

"'Cause no body will show up."

Sans couldn't help it. He snorted in laughter. "good one. here's a better one. what does a skeleton order from..."

He trailed off as Sans looked into the corner of the room. There were red eyes glowing in the darkness. Sans froze. Terror gripped his soul, the same kind of terror that hit him when Red startled him or grabbed him unexpectedly. He was gripping Red's hand too tightly, but Sans didn't seem to be able to stop. 

Red didn't seem to be affected. A wall of bones came up between him and the eyes. Not seeing them helped. Sans shook off his fear, and brought up his own bone attack. When Red pulled him behind him – protecting him – Sans went with only a little hesitation

"It's good to see you haven't lost your edge, brother," said a voice. Sans blinked. He knew that voice. Even if he didn't, there was only one monster around who would called Red brother. Red let his attacks disperse and Sans did the same.

"Fuckin' hell, Boss," Red yelled. "Don't just loom out of the dark and not expect to get stabbed."

Red's brother scoffed. "You don't even have a knife on you." He stepped forward into the very edge of the light of the emergency lantern. "What are you doing down here?"

"we're working on the machine," Sans supplied. The other Papyrus's eyes slid to him. Assessing. Sans couldn't help but feel a little like he didn't measure up. 

The other Papyrus looked down at where Red and Sans were still holding hands. Then over at Red. One eyebone was raised. Red didn't back down. He tilted his head up defiantly, and tightened his fingers on Sans's. His brother smirked.

Sans had never wondered what it felt like for other people when he and Papyrus had one of their silent conversations. Now he knew. He wasn't sure he liked it.

"Are you going to introduce me, brother?"

"Boss, this is Sans." Red inclined his head towards Sans. His brother blinked. "Yeah, I know. It's complicated. I'm goin' by Red just to make things less confusin.'"

"Why isn't he the one with the nickname?" Sans almost laughed but managed to bite it back. He didn't know how Red's brother would take it. That statement just sounded so much like Papyrus. All wounded pride for his brother.

"Eh. It's kinda his world we're in. Figured his world, his name."

"That does make sense, I suppose." The other Papyrus's looked at him again. "I should have a new name as well."

"I can pick one for you," Red volunteered quickly. A little too quickly. 

"No. I know your sense of humor. I'll pick my own. Or this Sans can pick one," he said. "Go on."

_Impress me._ Red's brother didn't say the last word, but Sans heard it nonetheless. So many puns wanted to trip their way off his tongue. Sans held them back. His brother wouldn't appreciate them, and he doubted Red's would either. He wanted to make a good impression. So Sans did something he rarely did anymore.

He put in some effort.

"how about edge?"

"Edge?" Sans watched nervously as Red's brother considered his suggestion. "Acceptable," Edge said. "Thank you for not suggesting something more... punny."

"no problem. i couldn't think of any that quickly. guess i needed to bone up on them."

For a long second, Edge just stared at him. Then he sighed. Red laughed while his brother rubbed at the space between his eyes. "Brother, your shitty sense of humor spans across worlds."

"it is a universal trait, i guess," Sans replied. He pulled Red over to the cot in the corner and sat on it. The emergency lantern went up under the cot, dimming its light even further. "grab a chair. i expect you two have a lot to talk about."

"What about the machine?" Red asked. Sans shook his head.

"it can wait. this is more important."

"Sap," Red accused. The smile he gave Sans was worth putting off working on the machine for another night.

**Notes for the Chapter:**

> The joke that got cut off by Edge's appearance:
> 
> "What does a skeleton order from a restaurant?"  
> "Spare ribs."


	23. As bad as it is, remember, it could always be worse

**Summary for the Chapter:**

> Sans gives Toriel an update.

**Notes for the Chapter:**

> Well this turned out to be more intense than I intended. Sorry about that.

**23\. As bad as it is, remember, it could always be worse.**

Sans did not go to Toriel's house often. If he needed to talk to her, he caught her at school. If she asked about it, Sans had a dozen excuses handy. She never asked. He never had to lie to her or explain his remaining unease around Frisk.

Today though... today was different. He wanted to give Toriel an update on his theories as to why suddenly the world had under-the-bed residents and how they could possibly fix it. Last time had shown him that even when Sans tried to time it between classes, little ears were always listening at the school. Sans had already traumatized enough kids in his life (resets). He didn't need to traumatize any more.

He was kind of hoping the kid was out. No such luck. As soon he rang the doorbell, Sans could hear footsteps on the other side of the door that were too light and too fast to be Toriel's. At least he had a few seconds to brace himself before Frisk opened the door.

They froze as soon as they saw him, eyes wide and half-hidden behind an unruly fringe of bangs. Then they ducked their head, unaccountable shy. _Hello Sans._

"Hello kid." Sans both spoke and signed his words. "Is Toriel home?"

 _Yes._ Frisk stepped back from the door. Sans took the hint and stepped inside. If Frisk noticed that he never gave them his back, they didn't say anything. _I will get her._ They headed deeper into the house while Sans peeled off to sit on the couch.

He didn't have to wait long before Toriel appeared with Frisk at her heels. "Sans. What a pleasant surprise." Toriel sounded like she meant every word: that she was pleased to see Sans and surprised to see Sans there. "I wasn't expecting you."

Sans didn't need to be the judge to hear the unspoken question. _Why are you here?_ "hey tori. gotta update on the problem under the bed."

"Of course." Toriel said. She turned towards Frisk. "Could you give us a moment, child? There is something we need to discuss."

Frisk looked between Sans and Toriel. They hesitated. _I can help. What is wrong?_

Toriel shook her head. "This is something between myself and Sans. There is nothing for you to do." Her hand was massive as she put it on Frisk's shoulder. "I made cookies. They should be cool enough for you to eat."

It looked like they would argue. Sans was braced for it. Then they nodded once and headed into the kitchen. They even closed the door behind them.

"They have already save monsters once. I am not sure it is fair to ask them to save monsters again," Toriel said once Frisk was in the kitchen. Her voice was low. Sans wouldn't put it past the kid to be listening at the door. "And I do not think if they knew what was going on they would stay out of this."

"fair enough," Sans said. He couldn't deny that he was glad Frisk wasn't in the room. His feelings were complex. Sans remembered that they had killed Papyrus, and he had killed them. He also knew that they had freed the monsters. The kid remembered everything as well. Frisk didn't forced friendship on him, but it still existed. They didn't avoid each other, but they did limit their time together. "where do you want me to start?"

"Do you know why they suddenly appeared?" Toriel asked. Sans let out a small, self-conscious laugh.

"i have theories. me and red, uh... that's the other me, think it has something to do with a machine left by the royal scientist before alphys." Sans didn't bother saying Gaster's name. Toriel wouldn't remember him anyway. "there was some sort of power surge. we think that between that and the absence of magic on the surface that, when the two universes touched, the monsters of their underground were used by our universe to fill the void. it's a working theory right now, but we haven't seen any evidence against it."

He also didn't mention that the power surge was because he had left the machine plugged in. No need to go into all the details. The details were boring and Sans got enough shit from Red about his carelessness to ensure he wouldn't make the same mistake again. Instead he'd make completely new and interesting mistakes.

"How do we fix it?"

"we can try and reproduce the original reactions. make the universes touch again." Sans grimaced. "that doesn't mean it will necessarily fix things though. or at least fix things how we want them to be fixed."

Toriel cocked her head to one side, considering him. Sans didn't fidget. She wasn't dumb, even if science had never been her thing. It didn't take long for her to put the pieces together. "It could return them to their world."

Sans released a breath he didn't know he was holding. "yeah. that's one possibility. it could also make them part of this universe. or it could erase them completely and fill the void with another universe. overwrite them like you would overwrite a computer file" When Sans laughed, there was no humor in it. "it could also open a blackhole and collapse this universe, but... uh... that's pretty low on the long list of probabilities."

"There are no guarantees." Toriel frowned. "Can we really make a decision for all of those monsters?"

Sans didn't say anything. Hadn't he already made those decisions once? This time was only a little different. He'd let go of Papyrus dozens of times. Now he was being asked to let Red go. "you said it before, they need help."

"Do they want help?"

"one of them does. and i plan on helping him." No matter what.

Then he left before Toriel could talk him out of it.


	24. Most monsters will not hurt you. They enjoy your company during the day.

**Summary for the Chapter:**

> Drinking may not fix your problems, but it might fix the machine.

**Notes for the Chapter:**

> Normally, this chapter would mark the end of an arc and I'd take a two week break. But I think ya'll would hunt me down if I did that.

**24\. Most monsters will not hurt you. They enjoy your company during the day.  
**

In retrospect, purchasing alcohol to deal with his emotional vulnerability was not the most responsible thing Sans could have done. But fuck responsiblility. Sans was done being an adult for the day. A short trip to the store had produced a fifth of vodka, some cocktail mix, and a load of bad ideas.

Which was how he wound up laying on the floor of the basement with arm slung over his eyes to block the light. Sans would get up, but he'd had too many bad ideas already. At least he wasn't alone in drowning his thoughts in alcohol. Red was drunkenly banging on the machine in a rhythm that had the same tempo as pulse of his soul.

"percussive maintenance doesn't work. i tried already."

"Fucking. Piece. Of. Shit." Each slightly slurred word was accompanied by another clang. 

Red should be drunker than Sans was. He'd drunk the vodka straight from the bottle. Sans had at least mixed it with cocktail mix. It theory that meant he'd had less alcohol. That didn't explain why Red was vertical while Sans was afraid he'd lose the floor if he tried sitting up.

Spicy ketchup mixed with alcohol. Sometimes humans had the best ideas. They called them Bloody Mary's, which was just morbid, but the drinks themselves were tasty. Who was Mary? Sans had spent a few hours on the internet and found our Mary could either by a historical queen or a ghost that lived in the mirror. Which was ironic considering Sans was half in-love with a monster than lived under his bed and had been in his mirror. One whose magic was kind of the color of the drink. That reminded him of when they were fooling around and...

Yeah okay, that train of thought needed to stop. Sans was too drunk to be horny.

"I wanna move to the other side," Red said. He dropped the wrench he'd been using on the floor. Rude. He could at least put it back in the toolbox like Sans did. When he remembered to.

"that sounds like a you problem," Sans replied.

"Your fingers are around my ankle," Red replied. They sure were. Sans had to be touching Red, otherwise he faded away for the night. Especially in the light and definitely when he tried to move out from under the bed.

"again, your problem. i'm fine where i am." Sans tightened his fingers around Red's ankle, just in case he got any sort of ideas.

"Asshole."

"takes one to know one."

Rather than replying, Red started walking around. Since Sans wasn't letting go, he got pulled along like the world's boniest ball and chain. It helped that he was on a blanket. He'd pulled it off the cot. The floor was cold and hard. Sans had limits on how uncomfortable he was willing to be.

Red finally moved around to the panel he wanted. It was already unscrewed, the tiny screws carefully taped to the back of the panel so they didn't get lost. Sans wasn't sure where Gaster had gotten the screws for the machine. All he knew was that none of them were a standard size or even the same size. 

"think you're going to get it working?" Sans had his doubts. He'd spent months trying to get it working. The problem was that to understand it, you had to think like Gaster. Who the fuck wanted to think like Gaster? Not him.

"Gotta get it workin'. Don't have a choice," Red replied.

There was always a choice. Sans had chosen to let the kid near his brother, even when he'd known that it could lead to Papyrus's death. He could have chosen different. What did it say about him that he hadn't? Rather than think about it, Sans asked as question. "are you going to make any progress like this?"

There was a long pause. Then Red threw the screwdriver he'd been holding hard against the wall. Suddenly, Red started laughing. Sans uncovered his eyes to see what the joke was. The screwdriver was sticking in the wall. It was hilarious, but that was definitely not behavior Sans wanted to encourage.

"dude."

Instead of replying, Red sat down. His laughter faded into something that was almost crying. Almost. Sans couldn't see any tears. "I'm tired."

"lay down then." Sans pulled on Red's ankle hopefully. "we can work on it tomorrow."

"Yeah." It didn't sound like Red had much hope. Sans made a mental note to not let Red drink with him again. "Don't blame me if I puke on you."

"better not puke on me," Sans replied. It was the last thing he remembered saying.

***

Something woke Sans up. It might have been the pounding in his head. Or the acidic, fuzzy flavor of his mouth, which he shouldn't be able to taste without manifesting a tongue, and yet somehow could. Or the lingering ache in his magic. Or even the fact that he feels vaguely nauseated even though a complete lack of internal organs should make that impossible.

It wasn't the first time Sans had had to deal with a hangover. He usually slept through the worst of it. This time was different. Why?

Reluctantly, Sans opened his eyes. He was still down in the basement and still laying on the blanket on the floor. Someone had turned the lights off. Probably Red. How considerate. There was a space beside him on the blanket that held a slight depression, like someone had been laying there just a few seconds ago. Sans reached out a hand. It was still slightly warm.

There was also a faint hum in the room. That was new. Something flickered at the edge of his vision. Sans turned his head and felt like his soul had been dunked in ice. The hum? That flickering of lights? It came from the same source.

The machine was on.

**Notes for the Chapter:**

> The entire time I was writing this I kept hearing the lyrics from "Life's Been Good" by Joe Walsh.
> 
> _I go to parties, sometimes until four_   
>  _It's hard to leave when you can't find the door_


	25. You are developing a virtue by facing your fears: courage.

**Summary for the Chapter:**

> Red takes the final step.

**25\. You are developing a virtue by facing your fears: _courage._**  


Sans wanted to unplug the machine. 

He didn't. Sans was pretty sure if he did, it would take them years to get it working again. Red would be furious and rightly so. All that work they did down the drain. All those monsters trapped in a half-life under beds or in closets, a part of this world and not. Sans had never made decisions for people when they could make their own, and he wasn't about to start now. Even if he really, really hated the machine.

The other urge that gripped him was to tell Papyrus to leave town. Just go. Get as far away from the machine as he could. Which was also something Sans was not going to do. First, because it would just make Papyrus suspicious. Second, if opening a hole in time and space caused the universe to collapse into a singularity, nowhere on earth was going to be safe.

Sleep was impossible. Sans wandered around the house while Papyrus was at work. He'd already called in to his own job. He knew concentrating on anything was a useless effort. Hell, even running his illegal hotdog stand would be impossible. All he could do was wait for nightfall and for Red to appear.

Papyrus came home just as the sun was setting. Sans did his best to hide his feelings, but he knew he wasn't successful. His brother was the coolest though. He didn't push. Instead, he scolded him about lazing around the house all day and made a plate of spaghetti. Then he gave Sans a hug and moved into his room.

The sun set. Sans went up to his room to wait in the darkness. He didn't have to wait long. Soon he felt the familiar fear/adrenaline spike accompanied Red. Sans reached his hand under his bed. Bony fingers wrapped around his own.

"Hey," Red said as soon as he pulled himself out from under the bed with Sans's help. Then he got a look at Sans's face. "What's wrong?"

"machine is working," Sans said before Red could say anything else. The words just spilled out. "it started working after we went to sleep."

"Fuck," Red said.

"yeah." His finger's briefly tightened on Sans's wrist. "guess this is it."

"I thought we'd have more..." Red trailed off. Then he squared his shoulders. "Let's do this."

"now?"

"Better now than when we have another power surge and it fries the machine again, dumbass," Red replied. He took a deep breath and let it out. "We knew this was comin'. I gotta do it."

No he didn't. Sans wanted to tell him to wait. They could do it tomorrow. Next week. Next month. Never. He didn't. Instead, he led Red down the stairs and to the basement. Part of him hoped that Papyrus appeared so this would be delayed. Sans never did have that kind of luck. Papyrus stayed in his room.

Edge wasn't in the basement either. Another missed opportunity. Sans tried his best to not dawdle and go down the stairs at a reasonable pace. Red didn't urge him to go faster. 

Finally, they were standing in front of the machine. There was a low, unpleasant hum in the room that seemed to settle in Sans's teeth. Red glanced at him. Then he pushed the button. 

"You think it'll have the coordinates from the last glitch?" Red asked as glyphs and wingdings scrolled across the screen. Despite how relaxed his posture was, Sans could see the sheen of sweat on his skull. "Don't wanna wind up in some fluffy place where everyone shits rainbows and breaks into spontaneous song."

"if it doesn't, i don't think it'll matter much," Sans replied. "you'll be able to sing showtunes just fine. i believe in you."

"Fuck you," Red said without heat. The screen had stopped scrolling. Now there was just a blinking cursor and a prompt. Slowly, Red typed in S-T-A-R-T.

The machine whirred and clicked. There was a sudden buildup of pressure in the air that increased just shy of the point of being painful before it popped. Something tore open with a wet sound. When Sans and Red turned around, there was a hole floating six inches in the air.

"Well that's fuckin' disturbin'," Red said. Sans agreed. "Let's get this over with."

"wait," Sans said. Red stopped and looked at him. Sans didn't know what kind of look he had on his face. He didn't care. All he knew was that he couldn't let Red step through the hole in space and time without kissing him one last time. When he drew back, his hands shook. "good luck."

"See ya later." As if Red had no doubt this would work. As if Sans couldn't see the fear in his eyes.

Without a backwards glance, Red walked through the hole in reality and into the darkness.

**Notes for the Chapter:**

> There's nothing under your bed.  
> There's nothing in your closet.  
> Nothing waits in every darkness.  
> Nothing is the most terrifying thing of all.
> 
> \- Night Vale podcast twitter
> 
> And ya'll thought I ended the last chapter on a cliff hanger.


	26. Brush your teeth. Always.

**Summary for the Chapter:**

> Where we all find out what happened.

**Notes for the Chapter:**

> Special thanks to the lovely [Miome](https://archiveofourown.org/users/Miome/pseuds/Miome) who read the first version of this chapter, looked me dead in the eye, and said "You can do better." 
> 
> So I did. Thank you for all your help, sweetie.

  
**26\. Brush your teeth. Always.**

The sun was too bright. This was not something Sans had a whole lot of experience with. The Underground didn't have a sun. While he'd been only half in this universe, Sans could only come out when it was dark. Now? Now the sun was a big fucking pain in his ass.

His brother had said absolutely nothing to him about the whole situation, but Sans could feel the weight of his disappointment on the back of his neck like the gaze of an unknown enemy. Fuck. Like he didn't already know that he'd fucked up. He didn't need Papyrus's disappointment to remind him. 

Of course, Sans should have known his brother couldn't stay quiet forever.

"How long were you dating the other Sans?" Papyrus asked. His voice was syrupy sweet.

"No, we are not fuckin' havin' this conversation," Sans said. He kept his focus on the road they were walking along. Roads led somewhere, right? And if they got to a place with monsters – or hell, even humans at this point – then they could start asking questions. Like if anyone knew a couple of skeleton monsters.

"I was just pointing out that if you are dating someone, then in general, you should have some way of contacting them." 

"Look, it wasn't like I didn't know where Sans was. I was livin' under his fuckin' bed," Sans said. Or maybe he should think of himself as Red. Sans – the other Sans – was right. This was confusing as hell. "It wasn't like I needed to give him a call when I could literally reach out and touch 'im."

His brother did not look impressed with his reasoning. "I don't need any more details." Which was good, because Red hadn't planned on giving his little brother any details. "Still etiquette wise, the dating manual says..."

"Fuckin' hell Paps."

"... that you should exchange contact information by the second date at the latest. And you should get use to calling me Edge, since that now seems to be my name."

"I'm gonna shove that stupid datin' manual up your..." Red never got to finish his sentence. Edge smacked him on the top of his head half-way through. "What was that for?"

"The dating manual is a valuable resource," Edge said. "You should be grateful I've read it and can give you advice considering you are too lazy to open it. If you had followed the guidelines for proper courtship, you would have your boyfriend's number. We could have called him. Instead, we're going to have to walk until we find someone and then hope they know who your boyfriend is." 

The worst part was, Edge was right. If he had Sans's phone number, they could have gotten a lift. He could have let Sans know it worked. They were here. In this world. Completely in this world. Instead, Sans was probably worrying himself sick or thinking something went wrong. 

Nope. Red was just a dumbass as usual. He was going to fix this though. He was going to find Sans. Suck it, universal causality. Nothing was going to stop him.

***

Not knowing Sans and Papyrus's last names or addresses was definitely going to slow him down though. How big was the above ground? Bigger than Red had thought. It almost made him long for the Underground where everyone lived in everyone else's pocket, and was nosy enough to know what everyone else was doing.

Okay, not really.

***

Three weeks. That's how long it took to finally be standing outside the door of a modest house on a modest little street trying to get up enough courage to wring a doorbell. Red would never have found the place if it hadn't been for the old lady. Not the one from this world. The one from his Underground. She'd obviously taken charge of finding out where all her subjects were and had managed to track him and his brother down based on rumors of a couple of rough looking skeleton monsters. Crazy bitch. Red would never be able to repay her.

It was the middle of June and there were still Gyftmas lights up. It looked cozy. Was there any room for him in that coziness? Red wasn't sure. But he did know he'd never find out if he didn't ring the doorbell.

Suck it up. Do it. Red pressed the button.

There was the distant sound of barking from inside then someone moving around. Red began to sweat, and not just because he was wearing his jacket in the heat. What if Sans didn't want to see him? What if he'd moved on? What if he'd given up?

Too late now. The door was flung open.

"HELLO, HOW CAN..." 

"Hey, Papyrus," Red said. His not-brother just stared. "Couldn't get enough of your noodles, so I thought I'd come back. Sorry it took so long."

He wasn't expecting the hug. Red's first instinct was to pull back, but he squashed it. It felt good to be hugged. He didn't realize how much he needed that until it happened. "SANS! COME DOWN HERE. WE HAVE A GUEST."

"i'm coming." Red automatically looked to the top of the stairs. Sans moved slowly. Listlessly. There were circles under his eyes, and his movements seemed more rote than deliberate. He was half way down before he bothered to look to see who was at the door. 

When he saw Red, Sans froze. His eyelights narrowed to pinpricks. Red didn't know what to do. His mouth opened before he'd fully thought through was he was going to say. "Hey, Sans. My calculations were right. Little off on the spatial component."

"the other fell monsters showed up two weeks ago," Sans said quietly.

"Sorry 'bout that. We... uh, Edge and I... we didn't stick around when we showed up Underground. Didn't realize anyone else was there." Red rubbed nervously at the back of his skull. He could tell he was getting all sweaty, but didn't seem to be able to stop. "The Queen tracked us down couple a' weeks later. It's why I'm late."

There was a blip and then Sans was right in front of him. Red braced himself for anything. He wouldn't blame Sans for punching him in the face. Instead, Sans pulled Red into a hug. "asshole."

"S'rry." Red hugged Sans just as hard. It felt like coming home.

***

Red was getting ready for bed.

He'd already changed into his sleep clothes, which were not much different than his regular clothes. Comfy shorts and a T-shirt. He tried not to just roll out of bed and go through the day with the clothes he'd worn the night before. Not unless he was sure Edge would see. The look on his brother's face made wearing the previous night's clothes all day hilarious rather than depressing.

All he had to do now was brush his teeth. It didn't take long. Using mint toothpaste was weird, but Red was getting use to the tingly feeling it left in his mouth. He spit into the sink, gargled some water, and turned off the bathroom light. 

Everything was dark and quiet. He went out into the hall and to Sans's room. Their room now. There was a single lamp on. Sans was already in bed, and hogging every pillow he could. Typical.

"Gimme at least one pillow," Red said. Sans barely cracked an eye open to look at him. 

"Nope. My pillows now." 

"Nope," Red replied. He started poking Sans in the ribs. Sans swatted at his hands. Eventually, he decided that giving up a pillow was the best option. Red didn't hesitate to grab one as soon as Sans let go. If he wasn't quick enough, sometimes Sans snatched it back.

They kissed briefly before curling up against each other. Even though they didn't need to keep hold of one another anymore, Red's fingers found Sans's under the blankets. Sans didn't protest.

"goodnight, red."

"G'night."

**Notes for the Chapter:**

> Seven months after I started this thing, it's done. I've hit the point where I'm excited I completed it and also a little disappointed it's over. I do have at least one or two side stories I might finish over the next few months. But right now, I'm going to let me brain rest.
> 
> One last call out though. Chance-key did some absolutely [FANTASTIC fanart](https://chance-key.tumblr.com/post/189357623720/based-loosely-on-tsaikos-monsters-of) based on this story. I love Red's face in it. Love it.


End file.
